The Blue Cliff Record碧巖錄

Deshan Xuanjian had spent his life on the Diamond Sutra. He carried a commentary on it. When he heard that teachers in the south were saying that this very mind is Buddha, a teaching outside the scriptures, he set out to refute them.

The monks of the east and west halls at Nanquan’s were arguing over a cat. Nanquan picked it up and said: if any of you can say a word, I will spare it; if not, I will cut it in two. No one answered. He cut the cat in two.