Zen Master So Sahn (1520–1604) is a towering figure in the history of Korean Zen. In this treasure-text, he presents in simple yet beautiful language the core principles and teachings of Zen. Each section opens with a quotation - drawn from classical scriptures, teachings, and anecdotes - followed by the author's commentary and verse. Originally written in Chinese, the text was translated into Korean in the mid-twentieth century by the celebrated Korean monk Boep Joeng. An American Zen monk, Hyon Gak, has translated it into English.