Abraham takes his son to the rabbi for ritual circumcision. The rabbi opens his drawer, and takes out a scalpel to perform the op.
Abraham is a little concerned to notice that the scalpel does not gleam, and queries the rabbi.
"That's right" says the rabbi "It's made of wood, Juniper wood!"

After the op, Abraham asks the rabbi why he continues the practice, rather than leaving it to a doctor.
"Ah!" says the rabbi, "The pay may not be good, but I get to keep the tips".

Having, finally, understood the first two replies, Abraham asks what god the tips might be.
The rabbi shows him a small purse made from half a dozen foreskins sewn together. Abraham then points out that it is rather a lot of trouble to go to just for a purse.
The rabi replies "Yes, but if you rub it, it's a suitcase!"