Where is the Original Cavity of Spirit (Ziqiao 紫竅) located?

It is situated at the Trikuta, the point between the eyebrows, extending inward to the center of the brain. Laozi called it the “Passage of Heaven and Earth” (Tiandi Men 天地門). Therefore, he advised practitioners to concentrate upon this center in order to realize the Self-Nature underlying all things.

Within this center resides a subtle point no larger than a grain of rice. It is the midpoint between Heaven and Earth within the human body, the Microcosm. It is the cavity of Prenatal Vitality (Xiantian Qi 先天氣).

Yet it is not sufficient merely to know its location, for the cavity itself does not include the wondrous Light of Original Nature (Benxing 本性), symbolized by the Circle and referred to by Confucius as Perfect Virtue (Ren 仁).

The Book of Changes (Yijing 易經) calls it the Limitless (Wuji 無極). The Buddha called it Perfect Enlightenment. Daoists refer to it as the Elixir of Immortality (Jindan 金丹), or Spiritual Light.

All these names point to the same reality: the One True Prenatal Vitality.

Whoever truly knows this cavity may cultivate the Golden Elixir. Thus it is said:

“When the One is attained, all problems are resolved.”

Therefore, in practice, both eyes should be directed inward toward the center, focusing upon the Trikuta. In this manner the One is preserved within the Original Cavity of Spirit (Ziqiao 紫竅), neither through strain nor through laxity.

This is called “guarding the Spirit within its Original Cavity.”

It is here that Original Nature develops, and from here begins the Way leading to Eternal Life.

“If the Original Cavity of Spirit is not established, the True Breath (Zhenxi 真息) cannot be continuously maintained. Spirit will lack a foundation for sublimation, the alchemical agent will remain incomplete, and the Golden Elixir cannot be produced.”

This cavity within the Trikuta is the foundation of spiritual stability and the center of all things.

It possesses neither an external form that can be grasped nor an internal object that can be mentally seized.

To fix one’s attention upon it as a visible thing is to become attached to appearances. Yet to abandon awareness altogether leads only to relative emptiness.

How, then, should one cultivate this realization?

The correct method is to close both eyes and quiet the heart-mind (Xin 心), maintaining awareness of the Original Cavity of Spirit until the Light of Original Nature appears, thereby confirming the correctness of the practice.

The disciple should keep the mouth closed and allow the tongue to touch the palate, thereby stabilizing both Spirit (Shen 神) and Vital Energy (Qi 氣).

When thought is upright, the heart situated between Heaven (the head) and Earth (the abdomen) likewise becomes upright. When Spirit is pure, the Supreme Ultimate (Taiji 太極) is naturally understood.

If one reaches the state in which no thoughts arise, clarity and purity will gradually emerge.

In complete abstraction from sensory perception and in the utmost stillness, a white Light appears, illuminating the Empty Chamber (Xushi 虛室). Then the Golden Mechanism (Jinji 金機) flashes forth.

At that moment, the entire Essence of Heaven and Earth becomes spontaneously clear.