Ma-tsu was doing Zazen daily in his hut on Nan-yueh Mountain. Watching him one day, Huai-jang (Nanyue Huairang, Nangaku Ejo) 677-744, his master, thought, “He will become a great monk,” and inquired:
“Worthy one, what are you trying to attain by sitting?”
Ma-tsu replied: “I am trying to become a Buddha.”
Thereupon Huai-jang picked up a piece of roof tile and began grinding it on a rock in front of him.
“What are you doing, Master?” asked Ma-tsu.
“I am polishing it to make a mirror,” said Huai-jang.
“How could polishing a tile make a mirror?”
“How could sitting in Zazen make a Buddha?”
Ma-tsu asked: “What should I do, then?”
Huai-jang replied: “If you were driving a cart and it didn’t move, would you whip the cart or whip the ox?”
Ma-tsu made no reply.
Huai-jang continued: “Are you training yourself in Zazen? Are you striving to become a sitting Buddha? If you are training yourself in Zazen let me tell you that the substance of Zazen is neither sitting nor lying down. If you are training yourself to become a sitting Buddha, let me tell you that Buddha has no one form [such as sitting]. The Dharma, which has no fixed abode, allows of no distinctions. If you try to become a sitting Buddha, this is no less than killing the Buddha. If you cling to the sitting form you will not attain the essential truth.”