The Shangqing Dadong Zhenjing 上清大洞真经 The True Scripture of the Great Cavern of the Highest Clarity

Shangqing Dadong Zhenjing (The True Scripture of the Great Cavern of the Highest Clarity), abbreviated as Dadong Zhenjing (The True Scripture of the Great Cavern), also known as Santian Longshu (The Dragon Book of the Three Heavens), Jiutian Taizhen Daojing (The Daoist Scripture of the Supreme Truth of the Nine Heavens), and Sanshijiu Zhangjing (The Scripture in Thirty-Nine Chapters), is an early classic of the Shangqing School of Taoism. It belongs to the first volume of the Shangqing Jing (Scriptures of the Highest Clarity) and is also the most important volume among the Shangqing Jing. Before explaining Dadong Zhenjing, it is necessary to understand the origin of the Shangqing Jing.

According to Tao Hongjing's Zhengao (Declarations of the Perfected), Volume 19, Zhengao Xulu (Preface to Declarations of the Perfected), the Shangqing Jing was written in clerical script by Yang Xi, a native of Jurong, in the second year of Xingning in the Jin Dynasty (364). It was then passed on to Xu Mi and Xu Hui, who further expanded the text based on this version. As early as the Jin Dynasty, fake texts had been mixed into the Shangqing Jing. According to Zhengao Xulu, there was a man named Wang Lingqi at that time who obtained the Shangqing Jing from Xu Huangmin, the son of Xu Hui. After careful study, he believed that "the supreme law cannot be publicly propagated, and the essential words are hard to be explicitly revealed," so he privately added content, resulting in more than fifty chapters. For a time, fake scriptures prevailed, with the true and false, old and new mixed together, making it difficult to distinguish them.

By the Song Dynasty of the Southern Dynasties, the length of the Shangqing Jing continued to expand. At that time, the Taoist Lu Xiujing compiled it into 186 volumes, among which it is not excluded that some of the scriptures might have been forged by him. It can be seen from this that the Shangqing Jing was continuously expanded during its circulation and was not a work exclusively created by an individual at a certain time.

Dadong Zhenjing is regarded as the "first wonder among the three wonders" of Taoism. "Dadong" (Great Cavern) is the ideal fairyland of the Shangqing School. It is said that this scripture was originally stored in the Dadong Fairy Palace, hence the name Dadong Zhenjing. The Shangqing School reveres this scripture as the first among all Shangqing scriptures, claiming that "if one obtains Dadong Zhenjing, there is no need for the way of golden elixirs; reciting it ten thousand times will make one an immortal." Therefore, it has been handed down through the ages without interruption.

The Taoist methods described in Dadong Zhenjing mainly focus on reciting scriptures and contemplating deities. The Shangqing School believes that there are countless immortal officials in heaven and earth, among whom more than 30 emperors headed by "Gaoshang Xuhuangjun" (High and Supreme Void Sovereign) are the most honorable. It is said that the names of various deities are implied in Dadong Zhenjing. When practitioners recite the scriptures, contemplate the deities, chant incantations, and wear talismans, they can summon the true qi and auspicious smoke of the Supreme Sovereign to enter their bodies through the Niwan Palace (the upper part of the head), stabilize the spirit, consolidate the essence, untie the dead knots of the fetus, open the portals of life, block the portals of death, and thus merge themselves with the "deities" to achieve the eternal existence of life and nature. It can be seen that the Taoist methods in Dadong Zhenjing are a development of the method of reciting scriptures and contemplating deities in Huangting Jing (Yellow Court Scripture).

Today, the Daozang (Taoist Canon) contains several versions, such as the six-volume Shangqing Dadong Zhenjing, the ten-volume Taishang Wuji Zongzhen Wenchang Dadong Xianjing, and the two-volume Dadong Yu Jing. Among them, the six-volume Shangqing Dadong Zhenjing is a collated version by Jiang Zongying, the 38th patriarch of the Shangqing School at Maoshan in the Southern Song Dynasty. It is prefaced by Zhu Ziying, Mr. Guanmiao, the 23rd patriarch of the Shangqing School at Maoshan in the Northern Song Dynasty, followed by a postscript by Cheng Gongduan in the eighth year of Xianchun in the Southern Song Dynasty (1272), and a postscript by Zhang Yuchu, the 43rd Celestial Master of the Zhengyi School in the early Ming Dynasty. This is the popular version in Taoism.