Zen students stay with their teacher at least ten years before they would presume to teach.

Tenno finished his apprenticeship and started to teach.

One rainy day, he visited the great Nan-yin.

At the entrance to the temple, Tenno left his clogs and umbrella.

Nan-yin greeted him and asked in passing,

“You left your clogs in the vestibule.

Tell me, did you place your umbrella to the right or the left of your clogs?”

Tenno was stunned. 

He was not attentive at the time and could not give a response now.

Tenno stayed on and became Nan-yin’s disciple for six years

…until he perfected Zen in every moment.