Tendo Nyojo

The fiftieth patriarch was Priest Tien-t'ung ju-ching. He studied with Hsueh-tou. Hsueh-tou asked him, "Disciple Ju-ching, how can something that has never been soiled be cleaned?" The master spent more than a year [on this question]. Suddenly, he was awakened, and said, "I have hit upon that which is not soiled."