The Blue Cliff Record is a translation of the Pi Yen Lu, a collection of one hundred Zen koans - the paradoxical teaching stories used by Zen teachers to go beneath rational thought - accompanied by commentaries and appreciatory verses from the teachings of the Chinese Zen masters. Compiled in the twelfth century, by the great Zen master and poet Hseh-tou Chung-hsien it is considered to be one of the greatest treasures of Zen literature and an essential study manual for students of Zen.