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 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!”