Biyanlu 碧巖錄

Biyanlu 碧巖錄, also called Biyanji 碧巖集, and fully titled Foguo Huanwu Chanshi biyan lu 佛果圜悟禪師碧巖錄, is a Buddhist text from the Song period 宋 (960-1279) authored by the Zen (Chan) monk Foguo Keqin 圓悟克勤 (1063-1135). During Emperor Huizong's 宋徽宗 (r. 1100-1125) reign, when Keqin was abbot of the Lingquan Monastery 靈泉禪院 at Jiashan 夾山 near Shimen, Li Prefecture 澧州, he was asked by Zhang Shangying 張商英 (1043-1122) to add commentary and chants to Xuedou Chongxian's 雪竇重顯 (980–1052) Song gu bai ze 頌古百則 "One hundred old cases with verses", and the Biyanlu was compiled by his disciples.

The mountain of Jiashan was also called Blue Cliff (Biyan 碧巖), and this gave the book its title. Xuedou's Song gu bai ze expressed stories of Chan Buddhism (Chanzong 禪宗) in verse (jisong 偈頌), paying careful attention to rhetoric, and was highly valued in monastic circles. Keqin, in turn, added a summary-style "cue" (chuishi 垂示) before each "case" (gong'an 公案) and verse, appended concise explanatory notes (jiazhu 夾注) to individual lines, and then added his commentary and chants at the end of each chapter. This created a comprehensive work, which has been especially illuminating for Chan practitioners studying gong'ans.

The structure of Biyanlu employs 100 gong'an cases as its framework. Each gong'an is divided into three parts: first, the gong'an is presented alongside an introduction, called the "preface" or "foreword"; second, Xuedou's verse on the case, known as songgu 頌古, is quoted; third, Keqin's commentary is included.

The work has been highly instructive for practitioners studying koans and was referred to by contemporaries as the foremost book of the Chan/Zen school. Since its publication, scholarly branches of Chinese Buddhism gradually merged, and the "Chan spirit" increasingly blended with poetic expression. Later, Dahui Zonggao 大慧宗杲 (1089–1163), concerned that the text might mislead readers or overly emphasise language, ordered its printed editions to be destroyed. Nevertheless, the book continued to circulate, and works imitating its style continued to appear. In the history of Chinese Buddhism, the Biyanlu had a profound influence on the transformation of Chan practice, and it was even transmitted to Korea and Japan, where it came to be regarded as a classic.