Shoyoroku - Case 39: Joshu's "Wash Your Bowls" [1]

A monk asked Joshu, 
  "I have just entered this monastery. I beg you, Master, please give me
   instructions."
Joshu asked,
  "Have you eaten your rice gruel yet?"
The monk answered,
  "Yes, I have."
Joshu said,
  "Then wash your bowls."

[1]: see case 7 of Mumonkan.