Dogen - Permanence And Nature Of The Wind
MAYU, Zen Master Baoche, was fanning himself. A monk ap- proached and said, "Master, the nature of wind is permanent and there is no place it does not reach. Why then do you fan yourself?"
"Although you understand that the nature of the wind is permanent," Mayu replied, "you do not understand the meaning of its reaching everywhere."
"What is the meaning of its reaching everywhere?" asked the monk again. Mayu just kept fanning himself. The monk bowed deeply.
The actualization of the buddha-dharma, the vital path of its correct transmission, is like this. If you say that you do not need to fan yourself because the nature of wind is permanent and you can have wind without fanning, you will understand neither permanence nor the nature of the wind. The nature of the wind is permanent. Because of that, the wind of the buddha's house brings forth the gold of the earth and makes fragrant the cream of the long river.
from 'Enlightenment Unfolds - The Essential Teachings of Zen Master Dogen'