A priest says to his friend, the rabbi, that he has a perfect way of eating for free in restaurants. "I go in at well past 9 o'clock in the evening, eat several courses slowly, linger over coffee, port and a cigar.
Come 2 o'clock, as they are clearing everything away, I just keep sitting there until eventually a waiter comes up and asks me to pay. Then I say: 'I've already paid your colleague who has left.'
Because I am a man of the cloth, they take my word for it, and I leave."
The rabbi is impressed, and says: "Let's try it together this evening."
So the priest books them into a restaurant and come 2 o'clock they are both still quietly sitting there after a very full meal. Sure enough, a waiter comes over and asks them to pay.
The priest just says: "I've already paid your colleague who has left."
And the rabbi adds: "And we are still waiting for the change!"