At the end of the tax year, HMRC sent an inspector to audit the books of a Synagogue in Golders Green. While he was checking the books he turned to the Rabbi and said, 'I notice you have a lot of candles. But according to these records you don't buy them often. How come?
'Good question,' noted the Rabbi. 'We save the candle drippings up and send them back to the candle makers, and every now and then they send us a free box of candles.'
'Oh,' replied the auditor, somewhat disappointed that his unusual question had a practical answer. But on he went:
'What about the matzah purchases? What do you do with the crumbs?'
'Ah, yes,' replied the Rabbi, realising that the inspector was trying to trap him with an unanswerable question. 'We collect them and send them back to the manufacturers, and every now and then they send us a free box of matzahs.'
'I see,' replied the auditor, thinking hard about how he could fluster the know-it-all Rabbi. 'Well, Rabbi,' he went on, 'what do you do with all the leftover foreskins from the circumcisions you perform?'
'Here, too, we do not waste,' answered the Rabbi...
'What we do is save all the foreskins and send them to HMRC and about once a year they send us a complete dick.