Huangdi’s Canon of 81 Difficulties Illustrated Commentary 黄帝八十一难经纂图句解

Referred to in short as Sentence Explanations of the Difficult Issues, it was annotated by Li Xun of the Southern Song Dynasty.

It was roughly compiled in the 5th year of Xianchun (1269), consisting of seven volumes and included in the Tai Xuan Section of The Daozang.

Huangdi's Eighty-One Difficult Issues is traditionally attributed to Bian Que (Qin Yueren), a renowned physician of the Warring States Period. According to modern research, it should be a medical classic compiled by physicians during the Qin and Han dynasties, and was completed no later than the end of the Eastern Han Dynasty. Divided into eighty-one "difficult issues", the book uses the guise of the Yellow Emperor to explain medical puzzles and retains a wealth of ancient medical experience, with a particular focus on expounding the theories of meridians and collaterals based on the doctrines of Yin and Yang and the movement of Qi. During the Three Kingdoms Period, Lü Guang, the Prefect of the Imperial Observatory of the Wu State, was the first to write annotations for this classic, and it was also recorded in the official histories and bibliographies of the Sui and Tang dynasties. In the Southern Song Dynasty, Li Xun further annotated it based on the commentaries of his predecessors. His annotations synthesize the theories of various schools and present his own judgments, with particularly detailed discussions on the locations of nutrient qi and defensive qi, the pulse diagnosis methods related to zang-fu organs, as well as meridians and acupoints. At the end of the book, there is an appended essay titled Preface to the Annotated Illustrations of Huangdi's Eighty-One Difficult Issues, which summarizes the fundamental principles and points out the flaws in Yang Xuancao's annotated version that are detrimental to the original theoretical meanings. Currently, only the version included in The Daozang has survived, making it extremely precious.