The Gateless Gate, by Ekai, called Mu-mon, tr. Nyogen Senzaki and Paul Reps , at sacred-texts.com
A monk told Joshu: "I have just entered the monastery. Please teach me."
Joshu asked: "Have you eaten your rice porridge?"
The monk replied: "I have eaten."
Joshu said: "Then you had better wash your bowl."
At that moment the monk was enlightened.
Mumon's comment: Joshu is the man who opens his mouth and shows his heart. I doubt if this monk really saw Joshu's heart. I hope he did not mistake the bell for a pitcher.