Primordial Unity Collection 纯阳真人浑成集

Traditionally attributed to Lü Yan (Lü Dongbin), a Taoist priest at the end of the Tang Dynasty. Consisting of two scrolls, it is included in the Tai Xuan Section within the The Daozang.

As a collection of poems by Lü Yan (Lü Dongbin), according to the preface by He Zhiyuan, a Taoist priest of the Qingzhen school during the Jin Dynasty, over 200 poems by Lü Yan were discovered in a storage room and compiled into two scrolls. It was named Huncheng Ji ("Collection of Innate Perfection") "for its natural and unadorned quality".

Most of the poems depict the joy of immortals living freely beyond the mortal world and wandering playfully among humans. They propagate the impermanence of the mortal world, exhorting people to see through fame and fortune and cultivate the Dao to seek immortality. Many also discuss cultivating the mind and refining nature, asserting that "true nature comes with complete freedom" and "when not a single thought arises, how can myriad karma take form? Emptiness stretches boundlessly, with bright moon and clear wind".

Additionally, there are twenty-six poems titled Zui Xuan Yin (Ode to the Most Mysterious), which specifically chant and expound on Internal Alchemy (Neidan) practices. There are also sword immortal poems expressing the Taoist priest’s lofty spirit of eliminating evil and upholding justice, such as: "Beard stained with blood, eyes blazing like rings; breathing out clouds, anger fills the world. Intolerant of a thousand unjust matters, I vow to wipe out the fierce and stubborn with a single secret formula". This reveals his bold and unrestrained temperament.

Judging from the overall content of the book, its core tenets are similar to those of poetry collections compiled by Taoist priests of the Quanzhen Dao during the Jin and Yuan dynasties.