The most famouns Zen koan of all is a play on a Chinese proverb `It takes two hands to clap': Case 1
Master: `What is the sound of one hand clapping?'
Po-chang needed a master for his new monastery, so he called all his monks together
and set a pitcher before them saying:Master: `Without calling it a pitcher, tell me what is is'
Head monk: `You couldn't call it a piece of wood'
The cook walked up and kicked over the pitcher spilling the water and walked away. The cook was put in charge of the new monastery.
Case 3
A monk asked Ts'u-wei: `For what reason did Boddhidharma come from the West?"
Master Ts'u-wei answered `Pass me that chin rest'. As soon as it was passed the master hit the monk with it.
Case 4
A master was having tea with two student monks. He tossed his fan to one and said `What
is this?' The student opened it and fanned himself. `Not bad' said the master and passed the fan to the second student who closed the fan and scratched his neck with it and then opened the fan, placed a piece of cake on it, and offered it to the master.Case 5
Student: `What is the meaning of Boddhidharma coming from the west?'
Master: `No meaning'
Student: `In phenomena, what is true?'
Master: `The very phenomena are themselves truth.'
Student: `The how should it be revealed?'
The master lifted the tea tray.
Tung-shan asked: `What is your name, monk?'
`Pen-chi.'
Tung-shan said `Say something more.'
`I won't.'
`Why not?'
`My name is not Pen-chi.'Tung-shan allowed him entry to his monestary.
Someone asked `If you form an idea about something, it's only a mere resemblance, isnt it?'
The Master said `Even if you don't form an idea, it's still a mere resemblance.'
`How do these differ?'
`You're a man who doesn't feel pain and itching, aren't you?'
Someone asked `What do you think about? The moment discrimination arises, one becomes confused and loses one's mind?'
The Master said `Kill, kill!'
A monk asked master Chao-chou respectfully:
`Does a dog really have a Buddha-nature or not?'
Chao-chou said `Mu' (Chinese: nothingness, nothing)
Emperor Wu: `I have erected temples and supported monks. What virtue will come out of it?'
Boddhidharma, `No virtue.'
Emperor Wu, `What is the most important teaching of the holy principles the Buddha?'
Boddhidharma, `Emptiness, not holiness.'