《龍虎手鑑圖》

The Dragon-Tiger Mirror Diagram scripture elucidates the fundamental principles of alchemical practice (encompassing both internal alchemy [Neidan] and external alchemy [Waidan] in Daoist cultivation), primarily using the hexagram imagery from the Book of Changes (Yijing) to explain the Dao of alchemy. Its core teachings are:

1. Alchemical practice must follow the natural patterns of cosmic Yin-Yang transformation. As stated in the Yijing, Qian (representing Heaven, the father) and Kun (representing Earth, the mother) are the parents of all things, while the Kan (Water) and Li (Fire) hexagrams function like the axle and hub of a wheel, driving the rotation of Yin and Yang. In alchemy, the union of lead (representing Kan) and mercury (representing Li) mirrors the intercourse of Yin and Yang.

2. The text employs four key hexagrams as metaphors:

• Qian and Kun serve as the "gateway" to alchemy, just as parents give birth to all beings.
• Kan and Li act as the "axle" of alchemy: the Li hexagram (Fire), empty at its center like a wheel hub, and the Kan hexagram (Water), solid at its core like an axle, rotate together like a turning wheel.
• The waxing and waning of Yin-Yang resembles the emergence of Yin energy at the summer solstice (fifth month) and Yang energy at the winter solstice (eleventh month), forming an endless cycle.

3. The firing process (controlling furnace temperature and timing) must strictly adhere to these patterns:

• The Kan hexagram, with Yang energy within and Yin energy without, symbolizes the gradual growth of Yang and decline of Yin during alchemical refinement.
• Each six-day period constitutes one firing cycle, mirroring the moon's phases.

4. The text ultimately emphasizes that true alchemy allows the "Dragon and Tiger" (code names for lead and mercury) to circulate naturally, nourishing the myriad spirits (energetic aspects of the body) to attain immortality. This differs fundamentally from worldly pursuits of external elixirs.

(Note: The term "tuoyue" refers to an ancient bellows, metaphorically representing the opening and closing of Yin-Yang energies; the "Supreme Unity Jade Formula" [Taiyi Yujue] is a crucial alchemical oral instruction.)

The Dragon-Tiger Mirror Diagram scripture reveals the essential techniques of Daoist Neidan (internal alchemy) practice through metaphorical language, unveiling the mysteries of bodily cultivation:

When humans indulge in sensual pleasures, a lifetime of toil ultimately turns to dust. The true "spiritual medicine" isn't found externally but resides within one's own Shen (spirit) and Qi (vital energy) — formless yet supremely efficacious. When the body's Yin-Yang energies achieve perfect harmony, they crystallize into the Golden Elixir.

Refining this elixir is like using heaven and earth as the furnace and one's body as the medicinal ingredients. The unfathomable state of Yin-Yang transformation is called "divine operation." After nine cycles of purification (jiuzhuan), the resultant "returned elixir" manifests as the purest energy within the human body (Taihe essence).

Practice must follow natural rhythms: the four seasons' cyclical progression mirrors the dance of dragon (Yang) and tiger (Yin) energies between the water (Kan) and fire (Li) trigrams within. As heaven and earth alternate between day and night, the body's midnight (peak Yin) and noon (peak Yang) moments follow twelve celestial stems.

The alchemical secret lies in "spirit-governed firing" — regulating the process through mental focus rather than physical fuel. The body inherently possesses the Threefold Sacred Flame (sanhua fierce blaze), and blind pursuit of external substances only wastes the essence of sun and moon.

"Yellow sprouts" signify the first alchemical signs, corresponding to primordial cosmic energy (Zhenyi). Like spring buds heralding creation's vitality, while "white mercury" describes the three transformative stages of Jing (essence) during practice (the numbers three days, nine-six, and three-five represent cultivation cycles).

The text employs "azure dragon hiding fire" and "white tiger containing metal" as metaphors for Yin-Yang energy properties. Only by mastering their transformational patterns can one glimpse creation's mysteries. The alchemical cauldron (Xuanyao) requires no gold or silver — it symbolizes the Dantian (energy center), gateway to the hidden dragon's emergence.

The true secret lies in recognizing both the function of "presence" and the wonder of "absence." Formless true Qi circulates (flowing pearls) like the body's energy currents (Taihe), activating the whole system through the three Dantians' rotation.

For longevity, nourishing Qi becomes fundamental — maintaining pure Jing circulation through the three elixir fields (sanyuan). Worldly mineral medicines belong to Yin substance; only cultivating pure Yang elixirs can truly benefit the body. When Qi reaches fullness, it spontaneously generates myriad spirits, and through specialized breathing techniques (Huachi pool), true Qi ascends to immortality.

The supreme achievement involves ninefold elixir refinement until essence-energy rises to the crown (mudball palace), transcending triple-world constraints like a serpent shedding its skin. The "river chariot" signifies kidney essence (Kan-water represents kidneys), resembling the Dark Warrior's (water deity) rotating wheel that completes cosmic energy exchange within the microcosm.

This passage from the Dragon-Tiger Mirror Diagram explains the principles of Yin-Yang harmonization and Five Phases movement in Daoist Neidan (internal alchemy) practice:

The first section discusses the crucial timing for cultivation: when the dragon (symbolizing Yang Qi) and tiger (symbolizing Yin Qi) meet and merge within the Dantian (energy center, literally "elixir field"), their harmonious interaction resembles a flower bud blossoming. Practitioners must attentively follow the initial stirrings of nascent Yang Qi, maintaining long-term perseverance to comprehend its profundity—just as waiting for plum blossoms requires patience.

The second section explains essential alchemical substances: the essence within "divine water" (referring to oral fluids) represents "mercury" (symbolizing the Shen/spirit), corresponding to the wood phase of the east and spring's Yang Qi generation. The southern direction represents the fire phase, serving as the guiding force in cultivation. Only by discovering this Yin-Yang equilibrium can practitioners align with the true Dao.

The third section reveals the essential nature of alchemical materials: cinnabar (sha) originates from gold mines, while mercury (liquid metal) pairs with lead. This implies the metaphorical transformation from Waidan (external alchemy) to Neidan—immortals wouldn't casually disclose these mysteries to ordinary people, not because they withhold alchemical methods, but from concern that revealing celestial secrets might incur heaven's retribution (referred to as "celestial mandate reproaching past transgressions"). Here "dragon-tiger" refers both to actual alchemical ingredients and metaphorically to the Yin-Yang energies within the human body.