Alchemical Formula for the Inner Purification of the Gold Treasure; Secret Writings from the Golden Box of the Jade Purity, transmitted by the Immortal Qinghua
Yuqing jinsi qinghua biwen jinbao neilian danjue 玉清金笥青華祕文金寶內練丹訣, by Zhang Boduan. This text explains in detail inner alchemical theory and practice using pseudo-philosophical terminology. The main emphasis is on “circulation of the inner light,” and the “fire timing” or the various breathing topics.
The author, Zhang Boduan, or Zhang Ziyang 張紫陽, was a native of Tiantai in present-day Zhejiang province. As is common with many Taoist adepts, his biography combines fact and legend, and the dates of the main events in his life are not entirely certain. He was born in Tiantai, a district in the present-day southeastern province of Zhejiang, probably in 987. Having concluded his education with the highest degree, he undertook a career as an administrative officer in his district. Soon, however, he was accused of committing a major infraction in his duties and was punished with banishment to the remote south, in the Guangdong province. Around 1065 he moved to Sichuan, in the southwestern part of China, with an army commander that had hired him as advisor. While he was in Sichuan he met a master who transmitted alchemical teachings to him, and a few years later he wrote his work. Later he moved to the southern Yunnan province, where, having made sure that his work would survive him, he died in 1082.
Zhang wrote the Understanding Reality(悟真篇 Wuzhen pian), its appendices, and a few other texts, including the Four hundred words on the Golden Elixer （金丹四百字 Jindan sibai zi）and Alchemical Instructions on the Inner Refinement of the Golden Treasure, a Secret Text from the Golden Casket of the Jade Clarity Transmitted by the Immortal of Green Florescence) 玉清金笥青华秘文金宝内炼丹诀Yuqing jinsi Qinghua Miwen jinbao neilian danjue）
Zhang Boduan was additionally an authority on Chan Buddhism.
Biographical sources suggest that Zhang Boduan died in 1082 CE during the reign of Emperor Shenzong of Song, but disagree whether he was born in 983, 984, or 987. Zhang was honorifically called Ziyang Zhenren 紫陽真人, ranking him as a Daoist perfected person, one rank higher than an immortal in the celestial hierarchy.
The Complete-Reality School of Daoism originated in the 12th century with the Five Northern Patriarchs (Wang Chongyang and his successors). In the 13th century, Zhang Boduan posthumously became the second of the Five Southern Patriarchs in the so-called Southern Lineage". In Shaanxi, Hong Kong, and Singapore, there are Perfected Person Temples dedicated to Zhang Boduan.