The Yanxia fangyan 巖下放言 "Unstrained Words from the Foot of a Precipice", also written 岩下放言,
is a biji 筆記 "brush notes" style book written by the Northern Song period 北宋 (960-1126) author Ye Mengde 葉夢得 who has also authored the book Shilin yanyu 石林燕語. After his withdrawal from the post of military commissioner (jiedushi 節度使) of Chongqing 崇慶 he retired to Mt. Bianshan 弁山 near Wucheng 烏程, where he dug himself into his library where he studies the Confucian Classics and many other types of books, including Buddhist and Daoist writings. During these studies he wrote down his thoughts and deliberations and so compiled the book Yanxia fangyan. The bibliography Zhizhai shulu jieti 直齋書錄解題 says it was 1 juan "scroll" long, but the received version consists of 3 juan. The collectaneum Baihai 稗海 includes a 2 juan long book called Mengzhai bitan 蒙齋筆談 "Brush discussions from the Dream Studio", written by a master called Zheng Jingwang 鄭景望 from Xiangshan 湘山 whose content is identical with the Yanxia fangyan, except a few paragraphs. Zheng Jingwang lived somewhat earlier than Ye Mengde. His poem Yingchuan 潁川 is included in Li E's 厲鶚 collection Songshi jishi 宋詩紀事 where it is quoted as taken from the book Mengzhai bitan. Because the Yanxia fangyan was not cirulcating in a printed version, it was believed that Ye Mengde had just copied Zheng Jingwang's book. Yet from many statements in the book which refer to Ye Mengde's own life, career and studies (like the commentaries Laozi jie 老子解 and Lunyu shiyan 論語釋言), it can be seen that he must have been the author of the text, and that the Mengzhai bitan is a copy of Ye Mengde's book, and not vice versa.
The Yanxia fangyan includes notes about all types of literature, quotes various stories about history, customs and habits, and is therefore an interesting source on the culture life during the Song period. Very enlightening are the paragraphs about the Buddhist interpretation of the Classic Yijing 易經 "Book of Changes" by Shen Zuozhe 沈作喆, Wang Zongfu 王宗傅 and Yang Jian 楊簡. The book can therefore be seen as a forerunner of the great Song period thinkers that united Confucian, Buddhist and Daoist thought (sanjiao heliu 三教合流).
The Yanxia fangyan is part of the collectanea Siku quanshu 四庫全書, Shilin yishu 石林遺書, Guangutang suo kan shu 觀古堂所刊書, Xiyuan xiansheng quanji 郋園先生全書, and, as an abridged version, in the Shuofu 說郛, Wuchao xiaoshuo 五朝小說 and Wuchao xiaoshuo daguan 五朝小說大觀.
Source: Li Xueqin 李學勤, Lü Wenyu 呂文鬰 (1996). Siku da cidian 四庫大辭典, Changchun: Jilin daxue chubanshe, vol. 2, p. 1952.