Zen Master Ummon's ''Preaching Facing Oneness''

The Case

A monk asked zen master Ummon, ''What is the teaching of the Buddha's lifetime?" Ummon said, "Preaching facing oneness."

Engo's Introduction

Zen Master Yün-Men made it his principle to demand that an answer sentence always contain three things of importance:

A statement that "fits the wave" (i.e. responds precisely to the questioner and his question in space and time) ;
A statement that "encompasses heaven and earth";
Thirdly, that the answer dries up all streams of thoughts and feelings and kindly cuts off the questioner's tongue.

Try to grasp it here in this example.

Verse

Facing oneness! There is no parallel! He fitted the holeless hammer with a handle. From under the Jambu tree, laughter rings out: Ha! Ha! Ha! Last night the dragon got his horns broken. Remarkable, the old man of Shoyo; He has one tally here.