Shoyoroku - Case 50: Seppo's "What Is This?" [1]

When Seppo was living in a hermitage, two monks came to pay their respects.
When he saw them coming, Seppo thrust open the gate of his hermitage with his
hands, jumped out, and said, 
  "What is this?"
The monks also said, 
  "What is this?"
Seppo hung his head and retired into his hermitage.

Later, the monks came to Ganto. He asked them,
  "Where have you come from?"
The monks said,
  "From Reinan."
Ganto said,
  "Did you ever visit Seppo?"
The monks said, 
  "Yes, we visited him."
Ganto said,
  "What did he say?"
The monks related what had happened. Ganto said,
   "What else did he say?"
The monks said, 
  "Not a word; he hung his head and retired into his hermitage."
Ganto said,
  "Oh, how I regret now that in those days I did not tell him the last word!
   If I had told it to him, no one under heaven could do anything against him."

At the end of the summer practice period the monks came back to this
conversation and asked him about its meaning. Ganto said,
  "Why didn't you ask me about it sooner?"
The monks said,
  "We could not dare to ask you about it." 
Ganto said,
  "Seppo was born on the same stem as I, but he will not die on the same
   stem. If you want to know the last word, it is just this."

[1]: see case 51 of Hekiganroku.