Tokusan was studying Zen under Ryutan. One night he came to Ryutan and asked many questions. The teacher said: `The night is getting old. Why don't you retire?'
So Tukusan bowed and opened the screen to go out, observing: `It is very dark outside.'
Ryutan offered Tokusan a lighted candle to find his way. Just as Tokusan received it, Ryutan blew it out. At that moment the mind of Tokusan was opened.
`What have you attained?' asked Ryutan.
`From now on,' said Tokusan, `I will not doubt the teacher's words.'
The next day Ryutan told the monks at his lecture: `I see one monk among you. His teeth are like the sword tree, his mouth is like the blood bowl. If you hit him hard with a big stick, he will not even so much as look back at you. Someday he will mount the highest peak and carry my teaching there.'
On that day, in front of the lecture hall, Tokusan burned to ashes his commentaries on the sutras. He said: `However rich the teachings are, in comparison with this enlightenment they are like a single hair to the great sky. However profound the complicated knowledge of the world, compared to this enlightenment it is like one drop of water to the great ocean.' Then he left the monastery.