The Wen Shi Zhen Jing (文始真經) is attributed to Yin Xi (尹喜), the legendary Guardian of the Han Pass (Han Gu Guan 函谷关), who according to tradition received the Tao Te Ching directly from Laozi as the sage departed westward. Yin Xi is also known as Guan Yin Zi (关尹子 — Master of the Pass), and the text is sometimes referred to by this name. He is venerated in the Taoist tradition as one of the earliest transmitters of the Dao’s innermost teachings.

Philosophically, the Wen Shi Zhen Jing is structured around a sequence of nine numerological chapters, each named after a cosmic number and its associated symbol. The text synthesizes cosmology, inner alchemy, and the metaphysics of the Dao, presenting a complete vision of reality from the primordial unity of One Universe through the transformative power of Nine Medicines. It draws on the same Huang-Lao Daoist tradition as the Wenzi and the Huainanzi, while developing a distinctive numerological and alchemical framework.

The text was canonized during the Tang dynasty, when Emperor Xuanzong elevated it to the status of a Taoist classic alongside the Tao Te Ching, the Zhuangzi, and the Wenzi. It has been studied and commented upon by generations of Taoist masters, and remains one of the most philosophically rich and least-known texts of the classical Taoist canon.