What is the sound of one hand?

Should you desire the great tranquility prepare to sweat white beads.

The spirit of meditation is the combating of self-willed thinking-it is a combat against the weight of one's feelings.

All beings are by nature are Buddhas, as ice by nature is water. Apart from water there is no ice; apart from beings, no Buddhas.

Meditation in the midst of activity is a thousand times superior to meditation in stillness.

What is this true meditation? It is to make everything: coughing, swallowing, waving the arms, motion, stillness, words, action, the evil and the good, prosperity and shame, gain and loss, right and wrong, into one single koan.

You know the sound of two hands clapping; tell me, what is the sound of one hand?