公案 · kōan

21Yunmen's Dried Shit-Stick雲門屎橛

雲門因僧問。如何是佛。門云乾屎橛

A monk asked Yunmen, "What is Buddha?"
Yunmen said, "A dried shit-stick."

Wumen's Comment 無門曰

雲門可謂。家貧難辨素食。事忙不及草書。動便將屎橛來。撐門拄戶。佛法興衰可見。

You could say Yunmen keeps a poor house: too broke to lay out a proper meal, too rushed to write a neat hand. The moment you ask, he shoves a shit-stick at you to prop the door open. You can see where the Buddhist teaching is headed.

Verse 頌曰

閃電光 擊石火 眨得眼 已蹉過
A flash of lightning, sparks struck from flint. Blink once and it's already gone.