Tan-Gen had studied with Sen-Gai since childhood. When he was twenty he wanted to leave his teacher and visit others for comparative study, but Sen-Gai would not permit this. Every time Tan-Gen suggested it, Sen-Gai would give him a rap on the head.
Finally Tan-Gen asked an elder brother to coax permission from Sen-Gai, which the brother did and then reported to Tan-Gen, "It is arranged. I have fixed it for you to start on your pilgrimage at once."
Tan-Gen went to Sen-Gai to thank him for his permission. The master answered by giving him another rap.
When Tan-Gen related this to his elder brother the other said, "What is the matter? Sen-Gai has no business giving permission and then changing his mind. I will tell him so." And off he went to see the teacher.
"I did not cancel my permission," said Sen-Gai. "I just wished to give him one last smack over the head, for when he returns he will be enlightened and I will not be able to reprimand him again."