Hsiang-yen Chih-hsien (Japanese: Kyôgen Chikan) (died 898) was a T'ang dynasty Ch'an master of the House of Kuei-yang. A Dharma heir of Kueishan Ling-yu, the story of Hsiang-yen's enlightenment is rather famous in the Zen tradition. According to his enlightenment story he had been an accomplished scholar of Buddhist sutras but for many years had made very little headway in his meditation practice. One day his master, Kueishan Ling-yu, asked him what his original face was before birth, to which he could not respond. This question became his koan, and he subsequently burned his sutras and set out to settle the matter. One day, while working, he heard the sound of a tile striking the ground and attained enlightenment. Additionally there is a koan attributed to Hsiang-yen in The Gateless Gate. The story is that of a man hanging in a tree by his teeth being asked why Bodhidharma came west. How the man is to respond became this famous koan.