《洞元子內丹訣》

Practitioners of Neidan (internal alchemy) do not refine ordinary lead and mercury (referring to mineral materials in Waidan/external alchemy), but rather the "true lead and true mercury" within the human body (metaphors for the Yin-Yang energies of Jing-essence and Qi). Ancient sages used lead and mercury as analogies to make these concepts more accessible to ordinary people. In truth, the key to alchemical practice lies in mastering the precise timing of the "firing process," just as picking flowers requires choosing the right season—yet many misunderstand this principle.

The northern direction represents water energy (Zhengqi/pure Qi), while the south symbolizes fire energy. Gathering these two energies of water and fire must be timed perfectly; missing the opportune moment renders even a century of cultivation futile. If one can make the "sun and moon" of the body (symbolizing Yin-Yang) return to their source, enabling water and fire to harmonize, spiritual attainment can be achieved swiftly. The so-called "elixir" actually refers to the three Dantian (energy centers) within the human body—where would real lead and mercury be needed?

The upper Dantian, located at the crown of the head, is called the "Mud Ball Palace" (Niwan Gong); the middle Dantian in the chest is the "Crimson Palace" (Jiang Gong); and the lower Dantian below the navel is known as the "Sea of Qi" (Qi Hai), also called the "cauldron." The essential method involves concentrating the energies of water and fire into these "cauldrons and furnaces." Specifically: reducing lust, treasuring Jing-essence, strengthening tendons and bones, and nourishing the brain—this cultivates the upper Dantian; embodying loyalty, filial piety, and benevolence while maintaining pure and focused intention—this refines the middle Dantian; and directing the water-fire energies into the lower Dantian's furnace to stabilize the foundation of Jing and Qi—this develops the lower Dantian. When all three Dantian are perfected, one transcends life and death.

Heaven and Earth endure eternally because of the orderly alternation of cold and heat, and the regular movements of sun and moon. High mountains have cloud seas, oceans have tides—these are all manifestations of Qi circulation. The human body follows the same principle: eyes correspond to sun and moon, intestines and stomach resemble rivers and seas, while the five organs align with the Five Phases—the liver with eastern Wood, heart with southern Fire, lungs with western Metal, kidneys with northern Water, and spleen with central Earth. Breath flows like clouds and mist, bodily fluids move like tides, blood vessels course like rivers, and the lower Dantian's essence chamber is akin to the ocean. Sages achieve longevity and ascension by aligning with these natural patterns through symbolic correspondences in their cultivation.

Yet foolish individuals squander their Shen-spirit through misguided efforts, clinging stubbornly to wrong methods—practicing day and night without results. Gathering Yin-Yang energies must strictly observe seasonal timings: during the fifth lunar month when Yin energy first emerges and Yang begins to wane, any deviation in timing will prevent the successful refinement of the internal elixir.

This passage elucidates key principles of Yin-Yang energy and timing selection in Daoist Neidan (internal alchemy) practice. Practitioners must comprehend the critical moments when Yang energy emerges—just as the winter solstice marks Yang's rebirth in the annual cycle, the Zi hour (11 PM to 1 AM) represents Yang's initial movement in the daily cycle. Missing these precise temporal windows results in vastly diminished cultivation effects.

The practice口诀 (mnemonic verses) reveal: ordinary references to lead and mercury (symbolizing Yin-Yang substances in the body) don't denote actual water and fire—true cultivation requires the harmonious interaction of Jing-essence (symbolized as the dragon) and bodily fluids (symbolized as the tiger). When the dragon (Qi) circulates, the tiger (fluids) must not remain static. During pivotal solar terms like the winter solstice, one should intensify practice, maintaining continuous energy circulation throughout the Zi hour. When Qi transforms into the dragon and fluids into the tiger, both can directly enter the Dantian (mysterious palace). Seizing this moment ensures alignment with the true path of cultivation.

The explanation on the Kan Palace (lower Dantian) clarifies: The Kan trigram represents the north, Yin energy, the moon, the tiger, and water—its structure shows Yang embraced by two Yin lines (Yang within Yin). Like water nourishing all things, this Yin-embracing-Yang energy constitutes the primordial source of creation. During the chaos of cosmic inception, this energy resembled water, with Yang energy like an egg yolk within its shell (Yin enclosing Yang). The principle of Yang emerging from Yin's extremity forms creation's fundamental law. Thus practitioners must guard the Kan Palace (lower Dantian), for Kan symbolizes the mother of all things—losing this root prevents growth.

The true essence of attainment lies in nurturing Jing-essence within the dark void (yaoming) and obtaining the authentic substance through the state of subtle awareness (huanghu). Just as noble persons preserve their purpose amidst turmoil, cultivators maintain right principles within chaos. The Yijing states "maintain sincerity in heart," yet fixating on celestial ascent invites peril. Jing-essence emerges from the Mysterious Feminine gate (Dantian), circulates through meridians, then returns to its source—forced dissipation leads to dissipation. Thus the Yijing's "action finds reward" refers to Yin-Yang energies jointly nourishing the Valley Spirit (Dantian's primordial Shen), circulating harmoniously through the meridian network.

This passage elucidates the essential techniques of Daoist Neidan (internal alchemy) cultivation concerning the "Kan Palace" (referring to the lower Dantian, located three inches below the navel). During practice, the movement of Qi must flow like water—neither overflowing nor stagnating—and must adhere to specific temporal rhythms. Consistent daily practice over a thousand days (approximately three years) is required for success; otherwise, there is risk of harm.

The text employs the metaphor of a "cauldron" to represent the human Dantian as the vessel of cultivation. When the refined essence (Jade Radiance, or Yu Hua) circulates within the body, it becomes as sweet as honey, ultimately returning to the Dantian to complete the alchemical process. This mirrors the teaching in the Yijing (Book of Changes): just as pottery (symbolizing the body) contains the essence of Yin-Yang energies (the fluids of dual Yin).

The cultivation formula states: Qi is like the dragon, saliva (Jin) is like the tiger—only when water and fire harmonize can True Yang be generated. Ordinary people fail to grasp the principle of Yin-Yang mutual generation, yet the fundamental truth lies in the mother-child (Yin-Yang) dynamic. At advanced stages of practice, one experiences saliva as sweet as fine wine, transported back to the Dantian via the "River Chariot" (a Neidan term denoting the pathway of essence and Qi circulation). By guarding the "Mysterious Feminine Gate" (a vital point in the Dantian), sitting in stillness, purifying the body through ritual bathing, one naturally kindles the Primordial Yang Fire. After a thousand days of successful practice, the Golden Elixir coalesces—hence the saying, "My destiny lies with me, not Heaven."

The third section discusses the "Li Palace" (the heart region), associated with the southern Fire position. The Li trigram is externally firm yet internally yielding, symbolizing the fierce and radiant Qi of the sun. Cultivation here requires balancing firmness and softness, transforming Yin and Yang. When Yang energy reaches its zenith, Yin arises; when Yin peaks, Yang emerges anew. Thus, the Kan trigram (Water) harbors True Yang, while the Li trigram (Fire) conceals True Yin.

This passage elucidates the principle of Yin-Yang harmony in Neidan (internal alchemy) practice. Cultivating Qi (vital energy) should never focus solely on unilateral operation of either the Kan palace (kidney water) or Li palace (heart fire) - the two energies of Yin and Yang must coordinate. Just as the golden crow (Yang) in the sun and the jade rabbit (Yin) in the moon require mutual illumination, pure Yin or pure Yang cannot endure.

The I Ching's saying "raising female cattle brings good fortune" serves as a metaphor: the ox corresponds to the earthly branch Chou (belonging to Yin), indicating that the northern Kan water needs gentle Yin energy to temper the dryness of Li fire (heart fire). Without such harmonization, problems will arise. During practice, one must fuse the Qi of Li fire (heart-mind) with Kan water (kidney essence), like containing illumination within the cauldron, which makes the practitioner's countenance radiant.

The text particularly emphasizes the heart's importance, calling it the "sovereign ruler" that requires careful moderation during cultivation. Imbalanced Yin-Yang leads to "sudden calamities" as described in the I Ching, resembling uncontrolled flames or discarded objects in their danger.

The subsequent mnemonic verses illustrate the method through metaphor: the Kan palace (kidneys) resembles a maiden while the Li palace (heart) resembles two young men, requiring Yin-Yang coordination. Practice involves guiding heart fire (dragon) with kidney water (tiger), circulating them within the Dantian (mysterious palace) like the moon attracting the sun, ultimately achieving the perfected state of the Three Powers (heaven-earth-human). The entire process underscores the principles of Yin-Yang equilibrium and water-fire complementation.

This passage explains the application of the "Ji Ji" hexagram from the Yijing (Book of Changes) in Daoist Neidan (internal alchemy) practice. The "Ji Ji" hexagram, representing water over fire, symbolizes the harmonious balance of Yin-Yang and the successful completion of all endeavors.

Practitioners should first absorb the energy of the Li trigram (symbolizing fire and the heart) after the Zi hour (11 PM to 1 AM), followed by drawing in the energy of the Kan trigram (symbolizing water and the kidneys). With Li below and Kan above, the water and fire energies achieve mutual regulation. At the initial stage of practice, when abundant Yang energy returns to the Dantian (lower abdominal energy center), it resembles the Yijing's description of "moistening its tail." The Yin energy of Kan leaves its original position to preliminarily combine with Li's Yang energy, though not yet firmly integrated—this is called "losing its adornment."

Through persistent practice for seven days, the Yin and Yang energies will harmoniously coexist. By guiding Kan energy to the lower Dantian to pair with Li energy, three years of such cultivation will yield results, just as the Yijing states "after three years of campaigning against Guifang, victory is achieved." Even elderly practitioners with declining vitality can replenish their primordial Qi by understanding and consistently applying the principles of the Kan and Li trigrams without interruption. Prolonged practice may ultimately lead to immortality—like using rags to plug a leaking boat, though crude, it effectively solves the problem.

The commentary further explains: prioritizing Li before Kan creates the water-fire mutual nourishment and Yin-Yang coordination. As fire and water energies enter the Dantian, this manifests as "moistening its tail." The Kan energy departs its original position to be received by Li—not through active convergence but through midway encounter—hence "losing its adornment." Seven days of perseverance brings harmonious interaction. The "three-year campaign against Guifang" refers to the extended cultivation period required (with Guifang representing Yin energy)—only after circulating Kan energy for a thousand days can success be achieved. Even aged cultivators who persistently refine Qi without slackening will naturally experience spiritual replenishment.

This passage explains the transformation from "Weiji" (Not Yet Fulfilled) to "Jiji" (Already Fulfilled) in Daoist Neidan (internal alchemy) practice, using metaphorical language to describe how adepts harmonize Yin and Yang energies.

The process begins with a symbolic encounter between genders: A practitioner from the south (the "Yellow Li Man," representing Yang) arrives at the sacred golden palace (Jinque), maintaining steadfast cultivation resolve. Then a beautiful maiden from the north (symbolizing Yin energy) emerges, riding the "River Chariot" (a term for Qi circulation pathways in Neidan) from the lower Dantian (Jade Gate) to actively unite with Yang. This Yin-Yang union follows cosmic patterns like heaven-earth interaction and sun-moon cycles, achieving "Jiji" (balanced state) during the midnight Zi hour (pivotal time of Yin-Yang transition).

"Weiji" represents the transitional phase where Yin energy begins emerging as Yang approaches exhaustion. Like the hexagram image of a young fox wetting its tail while crossing a river, it suggests temporary difficulty with eventual success. Practitioners must gather nascent Yin energy before noon (Yang's zenith) through specific breathing techniques ("drawing-in"), creating an internal cycle—first absorbing Kan (Water trigram) energy, then merging with Li (Fire trigram) energy.

When a wisp of Yin enters the Dantian (Great Granary) while still faint, this is the "Weiji" state. As Yang gradually fills the "cauldron" (lower Dantian), Yin transforms successfully into "ultimate fulfillment." This resembles supporting the weak with firm strength, like the Yi Jing's "pulling the wheel" metaphor—progressing steadily. Practitioners must balance firmness and flexibility, much as noble individuals transform others through virtuous influence.

Achieving "Jiji" brings blessings comparable to a nobleman receiving honors or a Daoist attaining longevity, echoing the Yi Jing's top Yang line about "confidence in celebratory drink"—symbolizing joyful accomplishment.

The conclusion emphasizes: Like the little fox crossing the river (symbolizing Yin), though initially weak, success comes through perseverance. Yin (Kan) harmonizes with Yang, achieving perfect balance. The noble path begins humbly before attaining glory—appearing delicate during "Weiji" yet radiant at "Jiji." When Yin and Yang occupy proper positions following cosmic rhythms, true accomplishment manifests.

A practice verse advises: Maintain focus like "locking the Mysterious Palace's gates" (guarding the spirit), embody the gentle poise of "two times eight maidens" (symbolizing optimal Yin receptivity), yet avoid excessive attachment.

This passage elucidates the essential principles of Yin-Yang interaction and timing (huohou) in Daoist Neidan (internal alchemy) practice, using the metaphor of conjugal union to explain cultivation techniques.

The practitioner resembles an unmarried maiden who must act discreetly ("unknown even to parents"). When Yang energy ("the great sun") emerges, one must seize the moment to enter meditative practice ("dragon palace"), requiring the catalyst of true Yang Qi ("the Yang lord rides his fiery chariot") to facilitate Yin-Yang union. This dynamic interplay of mutual restraint and generation ("Yin and Yang alternately control each other") constitutes the foundation of the longevity path.

Regarding the cultivation stages of "Weiji" (Before Completion) and "Jiji" (After Completion): Weiji hexagram symbolizes Yang energy taking the lead, while Jiji represents the harmonious blending of water (Yin) and fire (Yang). Practitioners must follow nature's sequence—first gathering lunar essence (Yin) then solar essence (Yang)—embodying the mother-child generative principle. The method involves: applying four Li (fire) hexagrams followed by four Kan (water) hexagrams, repeating this cycle twelve times to complete a microcosmic orbit.

The mnemonic verse advises: Timing should mirror celestial motions. Begin practice at dawn's first light and moonrise ("when the sun is born and the moon begins its course"), completing twelve orbital cycles nightly. Practitioners must synchronize with cosmic rhythms ("accompanying you through countless autumns"), emphasizing the critical importance of proper timing and location ("gather only when time and place align"), warning against forced practice during inauspicious moments.

The Qian (Heaven) hexagram section reveals cosmic origins: All things emerge from the primal Yin-Yang energies (Kan-Li), forming heaven and earth (Qian-Kun). Sun and moon traverse between them—viewed proximally, heaven-earth generates water-fire. Qian's virtue manifests as ceaseless vigor ("self-renewing without rest"), its Qi condensing to mustard-seed minuteness or expanding to fill the cosmos. The Way of Heaven stands sublime and sacred ("revered yet unapproachable"), its mysteries perceptible only to steadfast cultivators ("unremitting throughout the day"). Those attaining Qian's perfected state establish unshakable spiritual virtue, gaining creative power like heaven-earth. Practice requires gradual accumulation of celestial-terrestrial essences through impeccably timed absorption.

This passage explains the operational principles of the "Azure Dragon" (symbolizing yang energy within the body) in Neidan (internal alchemy) practice, using the hexagram lines of Qian (Heaven) from the Yijing (Book of Changes) to metaphorically describe cultivation stages.

At the initial stage of practice, when yang energy remains faint ("the Azure Dragon's first yang begins its journey"), it corresponds to Qian's first yang line: "Hidden dragon, do not act." Here, practitioners should avoid forceful exertion, instead maintaining patience like a nobleman content in humble circumstances while awaiting the proper moment. As yang energy gradually strengthens ("yang De finds resonance"), mirroring the second yang line's "dragon appearing in the field," the cultivator must reduce distractions, restrain desires, fortify moral cultivation as protective walls, wield benevolence as a shield, exercise careful speech and conduct, while profoundly contemplating mystical states.

Upon reaching the third yang line's "vigilant perseverance from dawn to dusk," practitioners must cultivate diligently day and night. Qian (representing heaven and yang potency) inherently lacks fixed form—as practice progresses, the body's vital Qi (yi qi) flows like jade nectar, permeating all spiritual apertures (ling yuan). After sustaining practice for a thousand days (approximately three years), one attains the "clouds moving, rain falling" state where Qi circulates freely to nourish the entire being.

The text emphasizes aligning practice with Qian's four virtues (yuan heng li zhen—origination, prosperity, harmony, and perseverance): During inception (yuan), accumulate virtuous thoughts; during development (heng), gather auspicious qualities; at maturation (li), align with righteousness; in stabilization (zhen), preserve fundamental principles. Like orchid roots growing underground before sprouting ("the divine mushroom's unseen roots take hold"), accumulated yang energy eventually manifests tangible effects.

The concluding verse summarizes: Early practitioners must comprehend Wuwei (non-action) principles—when the first dragon (nascent yang) returns to the Dantian (primordial crucible), maintain crystalline mental clarity. "Fire naturally seeks dryness, clouds follow dragons" illustrates how cultivation must harmonize with natural laws.

This passage expounds on the essential principles of harmonizing Yin-Yang and cultivating the Kun Palace (representing yin energy) in Daoist Neidan (internal alchemy) practice.

During cultivation, one must maintain Yin-Yang equilibrium, just as the Azure Dragon (yang energy) and White Tiger (yin energy) must resonate with each other. Rather than obsessing over Waidan (external alchemy) techniques like cinnabar refinement and mercury fixation, the true key lies in balancing internal Yin-Yang energies. The Dragon and Tiger (symbolizing yin and yang qi) must each occupy their proper positions, maintaining the mutual nourishment of water and fire (Yin-Yang symbols), thereby obtaining the primordial qi of heaven and earth.

The Kun Palace chapter specifically elucidates the cultivation principles of yin energy: the fundamental operation of heaven and earth relies on Yin-Yang balance. When yin qi reaches its zenith, it requires yang qi for harmonization; when yang qi becomes excessive, it needs yin qi for restraint. Once this mutual regulation is established, the Dragon and Tiger qi naturally stabilize. The characteristic of the Kun Dao (yin energy) is gentle compliance and tranquil stillness—all things are born and perfected through it. Practitioners must align with celestial timing, adjusting their breath (refining qi) according to seasonal nodes, synchronizing their internal Yin-Yang with the cosmic cycles of cold and heat.

The text cites hexagram lines from the Kun (Earth) trigram in the Yijing to illustrate cultivation stages: beginning with the cautious approach of "treading on frost, anticipating solid ice" (Line 1), progressing through the virtuous accumulation of "containing beauty, capable of constancy" (Line 3), until reaching the consummate state of "yellow garments bring fundamental good fortune." Practitioners must gather the primordial qi (Yellow Bell qi) within their bodies, achieving harmony throughout their limbs and bones. When Yin-Yang energies fully intermingle in the Dantian (the cauldron vessel), and yin qi reaches its peak, it naturally triggers yang qi's balancing action—manifesting the dynamic phenomenon of "dragons battling in the wilderness, their blood dark yellow."

In summary, Kun Dao cultivation requires alignment with celestial patterns, nurturing yang within yin, accumulating progress through subtle refinement, and embodying the earth's virtue of bearing all things. Through gradual harmonization of Yin-Yang energies, practitioners ultimately attain the perfect state of "virtue merging with the boundless."

This passage explains methods for harmonizing Yin and Yang energies in Daoist Neidan (internal alchemy) practice, focusing on the application of the Dui (representing joy) and Gen (representing stillness) trigrams from the Bagua (Eight Trigrams).

Timing is crucial in cultivation: During the third day of the lunar month when the new moon appears (known as "shengpo"), Yang energy is abundant while Yin is weak. At this stage, practitioners should draw the "Azure Dragon" Qi from the Li palace (heart region) using nine respiration cycles to replenish the deficient Yin. However, this supplementation must cease at full moon to prevent Yin-Yang imbalance.

By the sixteenth day, the situation reverses with dominant Yin and insufficient Yang. Here one extracts "White Tiger" Qi from the Kan palace (kidney region), employing seven respiration cycles to strengthen Yang. The "Yellow Matron" metaphorically represents the spleen earth in the central palace, while "the Celestial King has offspring" symbolizes the true Yang within heart fire.

The essence of cultivation lies in mastering timing: acting when appropriate and stopping when necessary. Like the relationship between mountain (Gen) and marsh (Dui) - first joy then stillness - this embodies the principle of the Sun hexagram: reducing above to benefit below, appearing as diminishment while actually fostering growth.

In practical terms, practitioners should suspend Qi circulation during the first and last three days of each lunar month, called "memo" (extinction), to accord with celestial rhythms. The口诀 (oral formula) states: When Yang is weak, circulate Azure Dragon Qi using nine breaths at inception; when Yang flourishes, increase White Tiger Qi with three or four breaths. The waxing and waning of Yin-Yang follows set patterns requiring self-regulation.

A critical reminder: cultivation must strictly observe celestial timing, particularly observing prohibitions during these six days (first and last three). Incorrect sequence or methods not only prove ineffective but may cause harm, just as ignorant actions contrary to principle can ruin households.

The "Chapter on Transformational Phenomena" in the Dongyuanzi Neidan Jue explains that during Neidan (internal alchemy) practice—the Daoist method of refining Jing (essence), Qi (vital energy), and Shen (spirit)—the transformations of Yin-Yang resemble the shifting lines of the Bagua (Eight Trigrams, the ancient divinatory symbol system). When the six lines of a hexagram activate, the trigrams emerge accordingly, with the stirring of the Zhen trigram (representing thunder) foretelling the manifestation of auspicious or ominous events.

Practitioners observing the fluctuations of Qi and discerning the waxing and waning of Yin-Yang must adhere to this principle. Specifically:

In cultivation, if one first applies the "fire timing" (a technical term referring to the method of regulating internal energy) followed by "water methods," the state of Jiji (the Book of Changes hexagram symbolizing the perfect harmony of water and fire) can be achieved. Conversely, applying water before fire results in Weiji (the hexagram representing an incomplete state).

Cultivating the Li trigram (representing fire) before the Qian trigram (representing heaven) leads to the Tianhuo Tongren hexagram (the "Heaven and Fire in Harmony" symbol), signifying the practitioner's alignment with the will of heaven and earth. If one first refines the Black Tortoise (the water deity of the north) and then the White Tiger (the metal deity of the west), the Dishui Shi hexagram (symbolizing command) forms—a realm where one receives celestial grace.

Examining these trigrams inversely reveals their distinct implications. The practice involving the Kan (water) and Li (fire) trigrams must be completed within nine months, with subsequent Kan-Li cultivation adhering to this cycle. By riding the Qi of Kan and Li as if taming a horse, the mystical transformation of Yin-Yang is accomplished after three months when the Dragon and Tiger (symbolizing the body's Yin and Yang energies) converge.

The "Chapter on Water and Fire" elucidates the crucial process of Yin-Yang transformation in Neidan (internal alchemy) practice. After ninety days of quiet cultivation, the practitioner must stabilize their Shen (spirit), sit upright with eyes closed in a quiet chamber, and use intention to guide the movement of water and fire (referring to the two Qi of Yin and Yang) within the body until the intention naturally dissolves.

The specific method involves: guiding the "golden crow" (representing Yang Qi, the sun) into the "moon palace" (the Yin position), ensuring the body's Yang Qi remains vibrant and does not dissipate; meanwhile, the "jade rabbit" (representing Yin Qi) enters the "Li Palace" (the seat of heart fire), where Yin and Yang merge like tranquil autumn water. These internal changes are imperceptible to outsiders, but the practitioner can personally experience the wondrous inversion of Yin and Yang—male practitioners will embody soft, Yin qualities, while female practitioners will manifest strong, Yang traits. It is akin to a woman (associated with the Yin Kan trigram) wearing yellow (associated with Earth) or a man (associated with the Yang Li trigram) donning black robes (associated with Water).

When a man achieves a body of pure Yang, his every gesture naturally exudes confidence; when a woman cultivates a body of pure Yin, her heart remains cool and serene even without fanning herself. The essence of this Yin-Yang transformation lies in activating the Yang line within the Li Palace (heart fire), forming the bodily manifestation of the Qian trigram (pure Yang) within. Do not mistakenly assume that the Li Palace contains only water (Yin)—water's nature is fluid and changeable, warming when near Yang Qi and cooling when near Yin water, its yielding qualities defying simple definition. Through this practice, "yellow sprouts" (early signs of the Golden Elixir) will naturally emerge within the body. If cultivation continues, it will circulate endlessly like a fully loaded "River Chariot" (the pathways of genuine Qi), ultimately coalescing into the Golden Elixir. With this achievement, even in times of famine, one will not suffer hardship, for the fruits of cultivation are entirely self-derived, requiring no external aid.

The "Chapter on Burning Demons" clarifies that "demons" are essentially toxins accumulated from grains and food, which emerge from the Kan Palace (the seat of kidney water) every five days and eventually erupt in the heart fire position as various harmful afflictions.

The key to cultivation is this: one must evade the disturbances of the four seasonal energies like the "fire beneath the sea" (the true fire of the kidneys). Only vigorous true fire can penetrate the obstructions of water (Yin turbidity). When Qi suddenly surges from the "Mystic Spring" (Dantian), it resembles a dragon advancing while a tiger retreats (the mutual support of Yin and Yang), directly entering the "Sun Palace" (the crown of the head). At this moment, heart fire and kidney water merge like troops deployed in perfect order—even if millions of demonic obstructions lurk in the Dantian, they will be subdued. In an instant, the "Three Corpses" (the three destructive desires of the body) are incinerated. The crucial point is to firmly guard the "Ghost Gate" (lower Dantian), preventing internal and external pathogenic Qi from intruding. All things seek to deplete human Jing (essence) and Qi—only through this practice can one reverse the process and seize the creative power of heaven and earth.

The Dongyuanzi Neidan Jue (Dongyuanzi's Internal Alchemy Formula) presents essential techniques for "the coupling of dragon and tiger" and "the application of primordial fire" in Neidan (internal alchemy) practice.

In the "Coupling Chapter," it explains that during cultivation, the "true dragon" (referring to the heart's Shen, or spirit) and the "true tiger" (referring to the kidney's Jing, or essence) must meet at the appropriate moment. Practitioners should avoid the "primordial fire days" (specific inauspicious dates) and periods of seasonal transitions. The method involves guiding intention: the Azure Dragon, long dwelling in the heart's fire (the Southern Peak), is led to meet the White Tiger, hidden within the kidney's water (the Northern Sea). When the "celestial mandate" (heavenly opportunity) descends, the Azure Dragon stirs with vitality, departing from its usual path, while the White Tiger emerges from the Mysterious Palace (Dantian, the energy center). During their encounter, one must remain tranquil, neither rushing nor forcing. Repeating this process three times allows mastery over the Qi of dragon and tiger—marking the potential for immortality.

The "Primordial Fire Chapter" clarifies that "primordial fire" is not ordinary fire but the true Yang concealed within the kidney's water (the Kan trigram). Though kidney water appears Yin in nature, it harbors the true Yang fire within. Sages accumulate this fire to gently nurture the Dantian, stabilizing the body's Shen and Qi. The practice method involves: during specific seasonal transition hours, first arranging the positions of Li (heart) and Kan (kidneys) and opening the heart's fiery citadel. The true Yang in the kidneys is as clear as sweet spring water and must be carefully guided. When this true Yang Qi breaks through obstructions, rising from the Dantian to the Niwan (crown of the head) before circulating throughout the body, it dispels internal Yin impurities, filling the entire being with pure Yang energy.

The Dongyuanzi Neidan Jue (Dongyuanzi's Internal Alchemy Formula) presents two essential techniques in Neidan (internal alchemy) practice: ritual purification and the mutual nurturing of mother and child.

The section on purification explains that practitioners must maintain physical and mental purity. The "bathing" described here is not ordinary washing with perfumed water, nor do immortals use common water. The true "divine water" originates from the most refined source—inexhaustible and boundless, seemingly subtle yet capable of encompassing heaven and earth. However, if used by those who are not sages, one may drown in it instead. The specific practice method involves guiding the body's Jing (essence) and Qi (vital energy) during the noon hour (when Yang Qi is strongest), following the direction of the Kan trigram (one of the Bagua/Eight Trigrams, representing water). This allows the Yang Qi (symbolized as the Golden Crow) to ascend while the Yin Qi (symbolized as the Jade Toad) settles. Through this alchemical fusion of fire and water, the practitioner can reverse aging and preserve youthful vitality. The key lies in transforming the fire of the Li Palace (heart) into water and converting the Kan Chamber (kidneys) into pure Yang. This exchange of Yin and Yang leads to a profound metamorphosis of body and spirit.

The mother-child section discusses the relationship between Shen (spirit, the mother) and Yi (intent, the child). Just as a child depends on its mother for nourishment, the mother also requires the child's protection. During practice, all three Hun (ethereal souls) and seven Po (corporeal souls) must be gathered and stabilized, with particular attention paid to the coordination of Shen and Yi. If the Shen (mother) and Yi (child) can remain united without scattering, the highest state of cultivation can be attained—much like how a serpent gathering its essence may transform into a dragon. Practitioners should emulate the ancient sages by embracing the method of "holding the One" (concentrating on the primordial Qi) to achieve perfect unity of Shen and Yi. Modern practitioners sitting in meditation are, in essence, also seeking this state of spiritual and intentional harmony.

The Dongyuanzi Neidan Jue presents two chapters on the essential methods and precautions for attaining immortality through Daoist cultivation.

Chapter Eighteen reveals the secret of practicing Neidan (internal alchemy, the Daoist discipline of refining Jing, Qi, and Shen): by preserving the primordial Qi in the Dantian (the lower abdominal energy center) and preventing its dissipation, one can achieve the Great Dao. The true fire cultivated in the Dantian becomes as sweet as honey—by maintaining unwavering focus and preventing dispersion, one’s skill will gradually deepen. At a certain stage of practice, the refined essence will naturally circulate to the Crimson Palace (the middle Dantian, located near the heart), forming an internal cycle. Progress may be slow in the early stages, but later it accelerates, ultimately leading to a state of effortless transcendence. However, one must guard against external disturbances, just as one locks doors to ward off thieves. Practitioners should cherish their cultivation and avoid carelessly dissipating their accumulated power.

The text specifically mentions that those who begin cultivation late in life, if facing death before achieving full realization, may employ the method of "huan" (evading calamities) to first attain the status of an Earth Immortal (a terrestrial transcendent), then continue refining toward celestial ascension. When sensing the approach of death, one must immediately enter meditative stillness and stabilize the Mysterious Pass (a crucial energetic aperture in practice). At this moment, immortals may appear to invite one to ascend to the heavens—yet one must discern carefully and remain steadfast in cultivation.

Chapter Nineteen, the "Divine Light Chapter," critiques erroneous practices prevalent at the time. Some Daoists, desperate to perceive "divine light" (spiritual radiance arising in practice), even gouged their eyelids—a forced approach that violates the Daoist principle of "following nature’s way." True divine light manifests naturally during predawn hours, when roosters crow, through genuine cultivation; artificial striving only leads further from the true path.

The core teaching of these chapters emphasizes aligning with natural principles rather than forcing progress. Neidan cultivation must proceed step by step, stabilizing key energetic centers until the corresponding states arise spontaneously. Practitioners are also reminded to discern auspicious and inauspicious conditions, maintaining unwavering composure at critical moments.

This passage describes the specific methods and precautions for Neidan (internal alchemy) practice in Daoism. During cultivation, one should sit upright facing east, close the eyes to calm the mind, and wait in a state free from thoughts and concerns. The practitioner may witness divine light manifesting—sometimes resembling the movement of the sun and moon, sometimes flickering like candle flames, appearing and disappearing as it rotates up and down. If no divine light appears after prolonged sitting, or if one fails to sense it for three consecutive days, it indicates insufficient foundational aptitude, and the practice should be discontinued immediately.

The oral instructions advise: when practicing with closed eyes in a quiet chamber, extraordinary visions often appear at midnight. These phenomena vary—sometimes flashing like lightning, sometimes floating like waves; at times as bright as the sun and moon, at others shimmering like multicolored spirit pearls. If no such visions manifest, one must cease practice immediately and retreat from worldly distractions to seclude oneself in renowned mountains. Like gazing into a mirror, repeatedly observe oneself and carefully contemplate the essential teachings of cultivation. When the practice matures, one may shed their mortal form like a cicada emerging from its shell.

Chapter 20 of the Zongyao Pian ("Essential Summary") explains the hexagram principles underlying cultivation: practice should avoid stormy weather, resuming only after wind and rain have passed. The Kan (Water) and Li (Fire) hexagrams represent water and fire, and divination should not be performed on the last day of the lunar month. A complete cultivation cycle consists of twelve lines (yao) and thirty-six months. The harmonization of water and fire requires nine months, followed by another nine months to achieve Yin-Yang balance, and a final nine months to complete the positioning of Qian (Heaven) and Kun (Earth), totaling a thousand days of cultivation.

For those with depleted Jing (essence) and Qi (vital energy), a thousand days of practice are likewise necessary to replenish primordial Qi. This is because the Kan hexagram contains a single Yang line trapped between two Yin lines, mirroring the natural principle of fire born from water. Indulgence in desires exhausts Yang energy, and when Yang is fully depleted, death ensues—hence the imperative to restore Qi through cultivation. The movement of Heaven and Earth’s Yin and Yang, the dynamic interplay of strength and gentleness in motion and stillness, are all reflected in the transformations of the hexagrams. Celestial phenomena include the sun, moon, and stars; terrestrial phenomena encompass mountains, rivers, and vegetation. The six lines (yao) transform, Yin and Yang interact, giving rise to natural occurrences such as wind, rain, thunder, and lightning.

This scripture reveals the mysteries of Yin-Yang transformation and Neidan (internal alchemy, the Daoist practice of refining one's Jing, Qi, and Shen). The changing seasons and alternating cold-heat cycles, like the movement of sun and moon in heaven, all manifest the mutual transformation of Yin and Yang energies.

When the dragon (symbolizing Yang energy in the body) soars, clouds must follow; when the tiger (symbolizing Yin energy) leaps, wind inevitably arises. To cultivate the union of dragon and tiger (harmonizing Yin-Yang), one must approach with harmony rather than opposition, subduing and guiding rather than indulging restlessness. Indulgence harms the body, while harmony brings endurance; endurance leads to strength, strength to longevity—this is the foundation of virtuous achievement for sages.

The sages used the hexagrams of the Yi Jing (Book of Changes) to illuminate the Dao of existence and dissolution. "Change" means transformation, and only through comprehending the Dao can one master transformation. "Symbol" means imitation—through contemplation and imitation, one connects with divine consciousness (primordial spirituality), which is the key to longevity. Thus, the noble person understands advance and retreat, strength and softness, turning night into day and Yin into Yang, maintaining stillness amidst chaos while cultivating diligently in tranquility. Immersed in savoring, joyfully studying, observing spiritual light (luminous phenomena during practice) in movement, and contemplating the Hun (ethereal soul) and Po (corporeal soul) in stillness. Pursuing truth across vast distances, results will manifest within a thousand days—such practice naturally receives heavenly protection, with all affairs becoming auspicious.

The patterns of heaven and earth's movement become clear when observing celestial phenomena above and terrestrial patterns below, revealing the principles of the hidden and manifest. Tracing life to its origin allows penetration of life-death mysteries. Scattered Hun (spiritual energy) condenses into Shen (spirit), while primordial Qi (fundamental life energy) generates all things. Both Shen and physical form must remain complete—any leakage causes collapse like a torn sack. Those unaware of this principle find wandering souls becoming demons; demonic speech manifests as ghosts. Ghostly phenomena actually reveal gain and loss—losing the Dao makes ghosts, attaining it makes deities.

Following the essence of sun and moon, harmonizing with dragon-tiger nature (Yin-Yang characteristics), emulating heaven-earth's cyclical perfection, penetrating day-night's hidden-manifest transformations. Shen has no fixed form yet manifests responsively; Change has no concrete shape yet generates all phenomena. Between movement and stillness, who can fathom the profundity of Yin-Yang Dao? What appears as life may be death; what seems death may be life—those aligning with Yin-Yang transformations will flourish. The sage's Dao is used daily by common people unknowingly. Sages comprehend reality through embodying the Dao—this is benevolence; the wise gain insight through studying patterns—this is wisdom. Treasuring truth for destined encounters, the noble person's abundant virtue renews daily. As the Yi Jing states: "Daily renewal constitutes abundant virtue; continuous generation constitutes Change." Dwelling peacefully in stillness reveals heaven's movements; through one's spiritual light, Yin-Yang transformations become perceptible. Above modeling Qian (heaven's Yang strength), below following Kun (earth's Yin receptivity)—the Dao of Qian-Kun is fully contained herein.

This scripture elucidates the relationship between the cosmic interplay of Yin-Yang and the principles of human life, revealing how practitioners may penetrate these profound mysteries.

The opening section describes the unfathomable transformations of heaven and earth, where the alternation of Yin and Yang follows discernible patterns. Day and night, the turn of seasons—these seemingly opposite states in fact depend upon each other. Those who penetrate these transformational laws are said to have attained "penetrating insight" (Dong), while those who truly comprehend their profundity achieve "mysterious understanding" (Xuan).

Chapter 21, "Expounding the Mysteries," further explains: Though heaven and earth have no fixed form, they give birth to all things; though male and female have no predetermined appearance, they generate offspring. The emergence of life from nothingness accords with the great Dao, while the return to nothingness stems from ignorance. Practitioners must comprehend the dialectical relationship between "being" (you) and "non-being" (wu).

Regarding human life cycles specifically: At birth, a boy's Yang energy remains pure (symbolized by the Qian hexagram). Before age ten, his primordial Qi remains undispersed, with the six senses undisturbed. Around ten, preferences and aversions emerge—this marks the movement of the initial Yang line transforming into a Yin line, changing the hexagram to Gou (one Yin line meeting five Yang lines), symbolizing the first stirrings of desire. By twenty, the capping ceremony of adulthood brings social restraints and marital bonds, further intensifying inner cravings.

Through these Yijing (Book of Changes) hexagram transformations, the text illustrates how the body's Yang energy gradually dissipates with age, subtly advising practitioners to grasp life's primordial source and return to original purity. The mentioned Qian hexagram represents pure Yang, while Gou signifies the initial emergence of Yin—both being crucial concepts in Daoist Neidan (internal alchemy) practice.

This passage describes the gradual decline of yang energy in the human body with age, using imagery from the Yijing (Book of Changes). Around thirty years of age, a person resembles the "Dun hexagram" (Mountain over Heaven, symbolizing retreat), where the two yang lines (representing yang energy) begin to withdraw. At this stage, yin energy starts to grow while yang energy hasn't fully dissipated—just as a noble person distances themselves from petty individuals, practitioners must restrain desires. Desires deplete the body, and when yin energy is dominant, one must be especially vigilant against indulgence, preserving yang energy through retreat.

In the prime of adulthood, when vitality is strong, establishing a family and career often leads to three major drains: serving one's country exhausts through constant official duties, seeking revenge fuels aggressive tendencies, and coveting wealth breeds insatiability, while pursuing status creates endless competition. Many fail to recognize that lust is an axe chopping at life's root, and rich food is poison corroding the intestines. This resembles the "Pi hexagram" (Heaven over Earth, symbolizing stagnation), where half the yang energy is already depleted—outwardly robust but inwardly weak, like a noble exterior masking a petty core. Without cultivation during this phase, essence (Jing) and vital energy (Qi) will steadily diminish. Thus, noble individuals moderate their diet, guard against lust, fortify their foundation, and preserve primordial Qi to counteract yin's encroachment.

By forty, with a house full of descendants yet undiminished desires, teeth and hair begin to fall out, mirroring the "Guan hexagram" (Wind over Earth, symbolizing observation), where only two yang lines remain. Here, the human heart resembles the hexagram's fifth line (symbolizing the sovereign position)—if desires remain unchecked, ruin follows. The wise observe their condition carefully, practicing restraint in intimacy and abandoning greed, using harmonized Qi to restore balance. Noble individuals who follow this path continue their refinement, while petty ones self-destruct. Those who neglect moderation at forty face nature's elimination; thus, diligent practice becomes crucial, using yang energy to replenish yin's depletion.

This scripture employs the hexagrams of the Yijing (Book of Changes) to illustrate the patterns of Yin-Yang energy transformation within the human body, revealing essential principles for nurturing life and cultivating the Dao (the Way).

When people reach their forties or fifties without following the Dao of health preservation, their Yang Qi (vital energy) weakens and becomes disordered, while Yin Qi grows stronger—much like the Bo hexagram (symbolizing decay). The Bo hexagram resembles plants withering in autumn, with the decline beginning from the bottommost line (Chu Liu), just as the legs of a bed rot first. The bed symbolizes the human body; when it breaks, one cannot rest peacefully, and when the body deteriorates, the Shen (spirit) has no place to reside. If one fails to awaken in time when Yin Qi prevails and "petty men" (negative energies) gain dominance, the consequences become irreversible, like a collapsing house.

By the age of sixty, if no remedy is sought, it is akin to city walls crumbling and houses collapsing—Yin Qi completely overwhelms Yang Qi, and the Hun (ethereal soul) and Po (corporeal soul) scatter. At this stage, the Kun hexagram (symbolizing Earth) represents a state of pure Yin, where the functions of the five viscera and six bowels decline, leading toward death. The souls ascend to Heaven or descend to Earth—following the Qian hexagram (symbolizing Heaven) brings life, while submitting to Kun brings death.

Yet those who understand this principle and persist in cultivation can reverse Kun’s tendency toward dissolution. Even beginning cultivation at sixty is not too late. By harmonizing the energies of the Kan (Water) and Li (Fire) hexagrams, practicing at the proper hours, and maintaining stillness and focus, one can revive Yang Qi—just as the Fu hexagram (symbolizing renewal) depicts thunder stirring beneath the Earth, restoring the vitality between Heaven and Earth. The key lies in seizing the right moment and measure in practice, preserving tranquility, and returning to the origin.

This passage elucidates the principles of harmonizing Yin-Yang and accumulating De (Virtue/Power) through Neidan (internal alchemy) practice. The core teaching advocates aligning with the Dao of Heaven, where the growth of Yang Qi eliminates Yin forces to achieve mind-body harmony.

When discussing the "Return Hexagram" (symbolizing the rebirth of Yang Qi), the text reveals that the fundamental operation of heaven and earth lies in the cyclical interplay of Yin-Yang. Ancient sage-kings would enter seclusion during the winter solstice, with merchants and travelers ceasing activities, emulating the quiescent state of cosmic nature. Practitioners must cultivate diligently without respite, maintaining profound stillness (deep meditative absorption), and through perfecting the second Yin line (referring to a specific cultivation stage), attain the state of True Yang—manifested as the "Approach Hexagram" (symbolizing flourishing Yang energy).

When Yang Qi above the marsh (Dui hexagram) meets the earth (Kun hexagram), we witness the imagery of the Approach Hexagram. Here, Yang energy revives vigorously while Yin forces, though still potent, gradually wane daily. Thus, the path of noble persons expands while that of petty persons declines. Practitioners must persevere unceasingly, never violating heavenly principles even during Yin-dominant months. If robust Yang Qi spreads steadily, no transgressions will occur.

The scripture then explains the "Peace Hexagram" (Earth over Heaven, symbolizing harmony), which results from accumulated Yang energy. Noble persons should accumulate De and cultivate Yang Qi to eliminate Yin forces. When the nine orifices remain unobstructed, limbs are nourished, and daily rhythms are regulated, various spiritual capacities manifest spontaneously. As Yin diminishes daily and Yang strengthens, with inner firmness and outer gentleness, all endeavors will proceed smoothly.

Finally, the "Great Strength Hexagram" (Thunder over Heaven, symbolizing potency) depicts thunder stirring all creation. Noble persons observe the Dao of Qian (Heaven) to fulfill its cosmic work. Maintaining profound stillness prevents demonic obstructions and evil thoughts. One should illuminate primordial Qi with authentic awareness, severing all distractions. Impurities are cleansed with True Water (pure internal energy), while ailments are treated with Original Fire (primordial Yang Qi). Residual Yin will ultimately be consumed by Yang flames, extinguishing the path of petty persons. Though internal vigor may radiate outward, its external expression remains gentle, ensuring uncontainable Yang vitality.

When the "Three Corpses" (Daoist concept of three malevolent spirits within the body) seek rebellion and the "Seven Po" (seven Yin aspects of the soul) prepare to disperse, they inevitably fear the practitioner's vigorous Qi and cannot manifest their envious nature. This occurs because abundant Yang De commands universal mastery.

This passage uses the hexagrams of the Yijing (Book of Changes) as metaphors for different stages of Neidan (internal alchemy) cultivation in the human body. The core idea is that as practitioners age, they must continually adjust their cultivation methods to replenish Yang Qi (vital energy) and eliminate Yin Qi, ultimately achieving a state of pure Yang.

In childhood (referred to as "youthful innocence"), the human body exists in a state of pure Yang, resembling the "complete Yang" condition. Around the age of ten, the first signs of Yang deficiency begin to appear, corresponding to the Gou hexagram (with the missing initial Yang line). If one begins cultivation at twenty, it aligns with the Dun hexagram; persistent practice at this stage can lead to the Tongren hexagram (Heaven over Fire).

By thirty, if one maintains true practice and replenishes the initial Yang line, they reach the Wuwang hexagram (Thunder beneath Heaven). At forty, practitioners must reflect on their faults and guard their original mind, corresponding to the Yi hexagram (Wind over Thunder). Continuing cultivation at fifty to supplement Yang Qi aligns with the Yi hexagram (Mountain over Thunder).

During cultivation: replenishing Qi to restore the second Yang line at twenty corresponds to the Lü hexagram (Heaven above Lake); restoring this line by forty matches the Zhongfu hexagram (Lake beneath Wind). If one persists diligently at forty, refining Yin to supplement three Yang lines, they achieve the Xiaochu hexagram (Wind above Heaven). By fifty, understanding these principles and further replenishing Yang Qi to restore the second Yang line leads to the Sun hexagram (Mountain above Lake), where rising Yang Qi diminishes Yin Qi.

At fifty, comprehending the principle of "diminishing" (Sun) and transforming the third Yin line into a Yang line brings the Daxu hexagram (Heaven beneath Mountain). By sixty, free from doubt and steadfast in cultivation, strengthening lower Qi and refining the fourth Yin line into pure Yang ultimately achieves the Dayou hexagram (Fire above Heaven). The entire process involves harmonizing the four primary symbols (Yin-Yang and Water-Fire represented by Qian, Kun, Kan, and Li), using hexagram transformations to guide Neidan practice.

Here, "Qi" refers to vital life energy, while "supplementing Yang and eliminating Yin" forms the central goal of Neidan - through specific cultivation methods, practitioners gradually fill the body with Yang Qi until achieving a pure Yang constitution. Each hexagram represents distinct cultivation stages and states, requiring practitioners to adjust methods according to age and spiritual attainment.

This passage discusses the crucial importance of Yin-Yang balance in Neidan (internal alchemy) practice, the Daoist method of cultivating Jing (essence), Qi (vital energy), and Shen (spirit). Improper regulation during cultivation disrupts this balance, creating complexities akin to the Bagua (Eight Trigrams) multiplying into sixty-four hexagrams. When Yang energy flourishes while Yin remains latent, the realm of immortals becomes visible; conversely, excessive Yin with diminished Yang causes the dispersal of human hun and po souls. Such soul dispersion leads to premature death, whereas perceiving the immortal realm facilitates "corpse liberation" - a Daoist method of transcendence.

Those who comprehend this principle observe natural laws and emulate them. They moderate food and desires, cultivate body and mind, and uphold the Five Constant Virtues (benevolence, righteousness, propriety, wisdom, and faithfulness) to purify conduct. Ordinary people, driven by desires, behave like thieves, while sages inversely "steal" the essence of heaven and earth. The orderly movements of celestial bodies - the sun and moon's revolutions, day and night's alternation - demonstrate how all things maintain their proper positions. Practitioners must control distracting thoughts as if closing the Ghost Gate, and rein in their intentions like tethering wild horses.

The human body mirrors the cosmos in miniature, with timing being crucial. One must circulate genuine Qi in accordance with celestial rhythms, gathering mental focus at opportune moments. By preserving original Qi without leakage, consolidating true Yang, and refining Yin energy to pure Yang state, the Qian trigram (representing heaven and Yang) becomes established while the Kun trigram (representing earth and Yin) naturally manifests its foundation. When Yang energy prevails and Yin dissipates, the purging forces between heaven and earth emerge visibly, like dragons and snakes fleeing in retreat.

Practitioners must subdue the Three Corpses (the three malevolent spirits residing in the human body according to Daoism) and expel various demonic obstructions, while regulating the movements of the Green Dragon (liver Qi) and White Tiger (lung Qi). Through sustained cultivation, the pure Yin of Li trigram (symbolizing fire) and pure Yang of Kan trigram (symbolizing water) gradually transform into each other, ultimately achieving the state where heaven and earth invert positions and Qian-Kun find their proper orientation. Thus external pathogens cannot invade while internal Yang flourishes naturally.

By preserving the primordial Qi without dissipation and maintaining luminous Shen (spirit), one awaits the moment of physical metamorphosis. When form and spirit separate, unity with the celestial is achieved. Though human lifespan has predetermined limits, proper nourishment can extend it. The nine orifices (sensory gates including eyes, ears, nose, and mouth) must be closed to external temptations: eyes abstain from beauty, ears from decadent music, nose from fragrances, mouth from delicacies, and heart from covetous thoughts. For sensory contact with external objects breeds desires that deplete life force. Therefore practitioners practice inner vision rather than outward seeking, firmly guarding the foundation of life.

This scripture elucidates the core principles of Neidan (internal alchemy) cultivation and the philosophy of self-cultivation. Practitioners must first regulate their Shen (spirit, referring to conscious activities), for the heart-mind governs the body like a monarch rules a nation, commanding all the "ten thousand spirits" (various vital energies within the human body). Indulging in desires and allowing the Shen to scatter leads to dissipation of life force.

The text outlines three essential precepts: the eyes abstain from beholding beauty, the heart refrains from coveting desires, and the mouth avoids craving delicacies. These form the foundation for preserving the body and attaining sagehood. Heaven and Earth nurture all beings with benevolent De (Virtue), yet may also destroy them through impartial natural laws—this reflects the Dao's operation. Just as grains and plants grow according to seasonal rhythms, humans must align their cultivation with nature's principles.

Regarding practice methods, one must harmonize Kan-water (kidney Jing/essence) with Li-fire (heart fire) in mutual regulation (representing the Neidan concept of "water and fire complementing each other"). The ancient kings' practice of seclusion during winter solstice exemplifies this. Through cultivation, the Shen within the human body can attain immortality—this explains the Daoist concept of "liberation through corpse" (one method of transcendence).

The cultivation process unfolds in three stages: First, stabilize the body, nurture the spirit, and sever distracting thoughts—small results manifest within a hundred days. Next, deepen meditation to accumulate greater achievements over a thousand days. Finally, divine radiance emerges, synchronizing with the movements of sun and moon. Whether minor or major accomplishments, the underlying principle remains constant.

Practitioners must maintain focus like a deaf person observing or a blind person listening—completely cutting off external disturbances. When the sun and moon complete three celestial cycles (representing cultivation periods), the Great Dao is realized. As the physical body declines, the primordial spirit achieves liberation. What is gained through cultivation must be preserved, using the Dao to restrain desires. While petty individuals indulge their cravings, noble persons abide in contentment and uphold the Dao—this constitutes the true path of cultivation.

This scripture elucidates the core principles of Neidan (internal alchemy), the Daoist practice of achieving longevity through breath regulation and mental cultivation. Practitioners must calm their Shen (spirit) and return to the primordial state, focusing their intention on the flow of Qi (vital energy). By quietly abiding in the meditation chamber and silently preserving this path of cultivation, one maintains a mind clear of distractions, thus attaining freedom to traverse various spiritual realms.

The text states that while the physical body decays, the spirit can endure eternally. Ordinary people who appear alive are actually progressing toward death, whereas those who attain longevity through cultivation experience true life. Like the transformations of Yin-Yang in heaven and earth—which may gather or disperse—the movements of sun and moon follow orderly patterns, with hardness and softness mutually transforming (referring to the interaction of Yin and Yang Qi). Perseverance in practice leads to endurance, and endurance culminates in flourishing vitality. Thus, the practitioner's foundation becomes solid, and the principles governing advance and retreat become clear.

By dissolving hardness into softness, one comprehends the Dao of Qian (heaven) and Kun (earth), representing the interplay of Yin and Yang. Therefore, sages cultivate in stillness, dwelling peacefully to pursue the highest state of practice. When the mind becomes as clear as a mirror, the true nature of spirits and deities becomes visible. Ordinary people unconsciously apply these principles daily without realizing it. Viewing all phenomena as transformations of Qi—manifesting as hardness in motion and softness in stillness—one need only observe these manifestations and await their cyclical changes to discern fortune or misfortune.

Those who understand these principles of cultivation may be called sages. This is the ultimate realm of spiritual practice.