The story goes:
21. The Sound
of One Hand
The master of Kennin temple was Mokurai, Silent Thunder. He had a
little protege named Toyo who was only twelve years old. Toyo saw
the older disciples visit the master's room each morning and
evening to receive instruction in sanzen or personal guidance in
which they were given koans to stop mind-wandering.
Toyo wished to do sanzen also.
"Wait a while," said Mokurai. "You are too young."
But the child insisted, so the teacher finally consented.
In the evening little Toyo went at the proper time to the threshold
of Mokurai's sanzen room. He struck the gong to announce his
presence, bowed respectfully three times outside the door, and went
to sit before the master in respectful silence.
"You can hear the sound of two hands when they clap together," said
Mokurai. "Now show me the sound of one hand."
Toyo bowed and went to his room to consider this problem. From his
window he could hear the music of the geishas. "Ah, I have it!" he
proclaimed.
The next evening, when his teacher asked him to illustrate the
sound of one hand, Toyo began to play the music of the
geishas.
"No, no," said Mokurai. "That will never do. That is not the sound
of one hand. You've not got it at all."
Thinking that such music might interrupt, Toyo moved his abode to a
quiet place. He meditated again. "What can the sound of one hand
be?" He happened to hear some water dripping. "I have it," imagined
Toyo.
When he next appeared before his teacher, Toyo imitated dripping
water.
"What is that?" asked Mokurai. "That is the sound of dripping
water, but not the sound of one hand. Try again."
In vain Toyo meditated to hear the sound of one hand. He heard the
sighing of the wind. But the sound was rejected.
He heard the cry of an owl. This also was refused.
The sound of one hand was not the locusts.
For more than ten times Toyo visited Mokurai with different sounds.
All were wrong. For almost a year he pondered what the sound of one
hand might be.
At last little Toyo entered true meditation and transcended all
sounds. "I could collect no more," he explained later, "so I
reached the soundless sound."
Toyo had realized the sound of one hand.
Explanation:
The
Essential Gateway to Truth by Means of Instantaneous
Awakening
7.Q: When there are sounds, hearing occurs. When there are no
sounds, does hearing persist or not?
A: It does.
Q: When there are sounds it follows that we hear them, but how can
hearing take place during the absence of sound?
A: We are now talking of that hearing which is independent of there
being any sound or not. How can that be? The nature of hearing
being eternal, we continue to hear whether sounds are present or
not.
Q: if that is so, who or what is the hearer?
A: It is your own nature, which hears, and it is the inner cognizer
who knows.
