The Blue Cliff Record (Biyan lu)

A collection of 100 Chan koans with layers of commentary, one of the central texts of Chan and Zen. In the 11th century the master Xuedou Chongxian selected 100 cases from earlier records and wrote a verse on each. Some decades later Yuanwu Keqin lectured on them, adding an introduction to each case, short remarks between the lines and longer commentaries on both case and verse; the result was compiled around 1125 and named after a calligraphy at Yuanwu's temple. The first case shows Emperor Wu of Liang asking Bodhidharma for the highest meaning of the holy truths and being told: 'vast emptiness, nothing holy'. Other well-known cases include Yunmen's 'every day is a good day' and Zhaozhou's seven-pound robe. Yuanwu's disciple Dahui Zonggao is said to have destroyed the printing blocks, fearing that students were memorising the commentary instead of practising, and the text was later reassembled and reprinted.

It is the most literary of the koan collections, and reading its layers of case, verse and comment shows how Chan teachers used language to point beyond language.