Tozan Ryokai

The thirty-eighth patriarch was Great Master Tung-shan Wu-pen. He visited Yun-yen and asked, "Who can hear the nonsentient preach the Dharma?" Yun-yen answered, "The nonsentient can hear the nonsentient preach the Dharma." The master asked, "Do you hear it?" Yun-yen replied, "If I could hear it, you would not be able to hear me preach the Dharma." The master said, "In that case, Liang-chieh does not hear you preach the Dharma." Yun-yen said, "If you still don't hear me preach the Dharma, how much less [can you hear] the nonsentient preach the Dharma?" The master was greatly awakened at this point and he spoke this verse: Wonderful! Wonderful! The preaching of the Dharma by
the nonsentient is inconceivable. If you try to hear with
your ears, it is hard to understand; When you listen with
your mind's eye, then you know it. Yun-yen approved.