Ma-tsu (709-788) was a disciple of Hui-neng, the Sixth Patriarch and author of The Platform Sutra, and was awakened when Hui-neng asked him why he meditated. To become a Buddha, responded Ma-tsu. At this Hui-neng began to polish a brick with a stone, and when asked what he was doing, replied, making a mirror. How can you make a mirror from a brick, asked Ma-tsu. How can meditation make a Buddha, replied Hui-neng. With this, Ma-tsu was enlightened.