...

A Zen Master was walking in silence with one of his disciples along a
mountain trail. When they came to an ancient cedar tree, they sat down
under it for a simple meal of some rice and vegetables. After the meal, the
disciple, a young monk who had not yet found the key to the mystery of Zen,
broke the silence by asking the Master, “Master, how do I enter Zen?”
He was, of course, inquiring how to enter the state of consciousness
which is Zen. The Master remained silent. Almost five minutes passed while the
disciple anxiously waited for an answer. He was about to ask another
question when the Master suddenly spoke. “Do you hear the sound of that
mountain stream?” The disciple had not been aware of any mountain stream. He had been
too busy thinking about the meaning of Zen. Now as he began to listen for
the sound, his noisy mind subsided. At first he heard nothing. Then, his
thinking gave way to heightened alertness, and suddenly he did hear the
hardly perceptible murmur of a small stream in the far distance.
“Yes, I can hear it now,” he said. The master raised his finger and, 

with a look in his eyes that in some way was both fierce and gentle, said, “Enter Zen from there.”
The disciple was stunned. It was his first satori – a flash of
enlightenment. He knew what Zen was without knowing what it was that he
knew! They continued on their journey in silence. The disciple was amazed
at the aliveness of the world around him. He experienced everything as if for
the first time. Gradually, however, he stated thinking again. The alert
stillness became covered up again by mental noise, and before long he had
another question. “Master,” he said, “I have been thinking. What would you
have said if I hadn't been able to hear the mountain stream?” The master
stopped, looked at him, raised his finger and said, “Enter Zen from there.”