Abraham and the Rabbi

Rabbi Goldstein was about to retire and decided he wanted to have something to remember his working life by.
He approached Abraham the local leather worker and produced a bag of 'offcuts' from his years of performing circumcisions.
'Abraham, make me something really special with these so I may remember all my years as a Rabbi' says the Rabbi, "yes Rabbi, I vill make for you something really special' replies Abraham.
Two weeks pass and the Rabbi returns to Abraham to see what he has crafted.
'Vot do you have for me Abraham' chortles the Rabbi, 'Ah Rabbi, I have something very special, a vollet' replies Abraham.
'Vollet, Shmollet, vot for I vont another vollet, I have hundred of vollets' protests the Rabbi, 'but this one is very special' replies Abraham, 'you rub it and it turns into an overnight bag'.