Shoyoroku - Case 94: Tozan Unwell

Tozan was unwell. A monk asked,
  "Your Reverence is unwell. Is there anyone who does not become ill?"
Tozan said,
  "There is."
The monk said,
  "Does the one who does not get ill take care of Your Reverence?"
Tozan said,
  "The old monk is properly taking care of that one."
The monk said,
  "How about when your Reverence takes care of that one?"
Tozan said,
  "Then the old monk does not see that there is illness."