The Gemara on today’s daf quotes a Mishna from Massekhet Shekalim (daf 18) that discusses the shofarot, or collection boxes, that were placed in the Temple. According to the Mishna in Shekalim, there were 13 collection boxes that were called shofarot, because they were shaped like a shofar with one end small enough for a coin to be placed into it and a larger end where the coins could be removed. (They were made in this way so that no one who came to deposit money would be suspected of stealing.) Each shofar was marked with the purpose of its money, so that no mistakes would be made. For example, one said “new shekalim” for the monies that were deposited for the fiscal year beginning in Nissan, one was marked “old shekalim” for the leftover monies from last year’s collection, etc.
Six of these shofarot were marked as collecting money for voluntary contributions to the Temple, that is to say, when a person dedicated money to the Temple for purchase of a sacrifice, if there was money left over it would be deposited in these collection boxes for the purpose of purchasing a korban ola – a burnt offering.
Rabbi Yehuda teaches that in this case, the skins of these sacrifices were not given to the kohanim. The Shita Mekubbetzet explains his position as requiring the skins to be sold so that other sacrifices could be purchased with the proceeds.
This is a reference to one of the stories in the Tanakh where we hear about the collection of shekalim (II Melakhim 12) in which King Yo’ash partnered with the High Priest Yehoiada in collecting money from the people and refurbishing the Temple. Yehoiada interpreted a difficult passage (Vayikra 5:19) to mean that extra money that is leftover after someone brought his korban asham should be used to purchase a korban ola, whose meat is burned, but whose skin is given to the kohanim. In this way that money is shared between the kohanim and the altar.