The True Grotto: The Supreme and Highest Clarity Inner Scripture 洞真太上上清内经

The author of The True Grotto: The Supreme and Highest Clarity Inner Scripture (Dongzhen Taishang Shangqing Neijing) is unknown.

Judging from its content and textual style, it should be a work composed by a Taoist of the Shangqing School (Supreme Clarity School) during the Northern and Southern Dynasties (420–589 CE). Consisting of one scroll, it is included in the Zhengyi Bu (Orthodox Unity Section) of the Daozang (Taoist Canon).

The scripture records the authentic names and secret taboos of the Nine Heavens, the golden formulas and true talismans for the authentic names of the Nine Heavens, the true surnames, secret taboos, and talisman formulas of the True Kings of the Nine Heavens, as well as the surnames, given names, and talisman formulas of the Jade Offices of the Five Directions in the Nine Heavens.

It is stated that the names and secret taboos of the Nine Heavens are all "heavenly scripts," concealed in the Golden Flower Palace of the Inner Chamber (Dongfang Jinhua Zhi Gong). The Primordial Heavenly King (Yuanshi Tianwang) ordered the Supreme Great Dao Lord (Taishang Dadao Jun) to transcribe these texts and interpret their correct pronunciations. If a Taoist practitioner obtains these authentic names and divine talismans, recites the authentic names and wears the talismans, they can then align their body with the true Dao, make their flesh and bones ascend together, and rise up to become an immortal.