Extraordinary Supplementary Commentary on the Book of Changes
Yu Yan in the Yuan Dynasty wrote the 1-volumed Extraordinary Supplementary Commentary on the Book of Changes ( 《易外別傳》 Yiwai Biezhuan ), with a preface by Emperor Shizong in the 21st year of the Zhiyuan era. The book, explaining the theory of Three Ways Unified and Normalized ( 《參同契》 Cantong Qi ) by Wei Boyang, describes the mystery of anterior-heaven circle middle ( 先天環中 Xiantian Huanzhong ) and considers it a priority for nourishing life to pursue this in one's own body. The book collects the Chart of the Supreme Ultimate of Mind ( 《心為太極圖》 Xin Wei Taiji Tu ) by Shao Kangjie, Chart of Anterior-Heaven Purple Middle of the Supreme Empty ( 《太虛紫中先天圖》 Taixu Zizhong Xiantian Tu ) by Zhu Ziyang, Chart of 64 Anterior Hexagrams ( 《先天六十四卦直圖》 Xiantian Liushi Si Gua Zhitu ), Chart of Earth Receiving Breath of Heaven (《地承天氣圖》 Di Cheng Tian Qi Tu ), Chart of Moon Receiving Light of Sun (《月受日光圖》 Yue Shou Ri Guang Tu ), Chart of Southern Li and Northern Kan in Post-Heaven Hexagrams (《後天卦離南坎北圖》 Houtian Gua Li Nan Kan Bei Tu ), Chart of Heaven-Earth-Kan-Li Trigrams, Chart of 8-7-9-6. Citing Three Ways Unified and Normalized, the Book of Changes of the Zhou Dynasty, the Book of Secret Correspondence (《 陰符經》 Yin Fu Jing ), and quotations of Shao Yong and Zhu Ziyang, the text explains the charts from the perspective of life cultivation with focus on "changes in the body". Collected in the Supreme Mystery Section (《太玄部》 Taixuan Bu ) of the Daoist Canon of the Zhengtong Era, the book is valuable for the study of the Daoist study of the I-Ching and cultivation.