Tangen was a student of Sengai since childhood. When Tangen was of twenty years of age he yearned to do comparative studies with other teacher, taking leave of Sengai.

It was customary of Sengai to give a rap on his head when ever he approached his master for permission. Tangen ultimately approached an elder brother to coax Sengai to grant him permission. The brother sought him permission according to his wish saying : "Its all arranged. I have fixed it for you and you can go ahead and start your journey"

Tangen then went to Sengai to thank him for the permission granted. Sengai as usual gave a rap on his head. Tangen, sad and upset related this to the elder brother who said " Sengai can't go back on his words after having granted permission. I will have a talk with him".

Sengai told the elder brother " I did not cancel the permission. I just wished to give him one last rap on his head, for when he returns he will be enlightened and I will not to be able to reprimand him"