As gross as it may sound, long ago, mohels (people who performed circumcisions) would sometimes keep and save the foreskins they circumcised. And grosser still is the fact that sometimes they would sew them together to make things. And once, a long time ago there was a mohel who performed more circumcisions than all other mohels. And one day he was talking to a friend of his and the friend asked, "You've performed so many circumcisions, have you made anything from the foreskins?" And the mohel said that yes, he had made a wallet from all the foreskins he had collected. The friend said, "You've circumsised so many children, you must have collected dozens of foreskins, and all you have made is a wallet?" And the mohel replied, "I know it's just a wallet. But when you rub it, it turns into a briefcase."