The Emperor Goyozei was studying Zen under Gu-Do. He inquired, "In Zen this very mind is Buddha. Is this correct?"
Gu-Do answered, "If I say, Yes, you will think that you understand without understanding. If I say, No, I would be contradicting a fact which many understand quite well."
On another day the Emperor asked Gu-Do, "Where does the enlightened man go when he dies?"
Gu-Do answered, "I know not."
"Why don't you know?" asked the Emperor. "Because I have not died yet," replied Gu-Do.
The Emperor hesitated to inquire further about these things his mind could not grasp. So Gu-Do beat the floor with his hand as if to awaken him, and the Emperor was enlightened !
The Emperor respected Zen and old Gu-Do more than ever after his enlightenment, and he even permitted Gu-Do to wear his hat in the palace in winter. When Gu-Do was over eighty, he used to fall asleep in the midst of his lecture, and the Emperor would quietly retire to another room so his beloved teacher might enjoy the rest his aging body required.