Chullin 135: Reishit HaGez, the Offering of Shearing

Today begin's Massekhet Chullin's 11th Perek.  We first are reminded of Devarim (18:3,4) where the butcher is called to offer the zero'a, foreleg, lechayayim, jaw, and kevah, maw, as offerings and Reishit HaGez, the Halacha obligating those who shear sheep to share that shearing with the priests.

In Yoreh De'a (333:11), the Shulchan Aruch teaches that the wool should be given at the beginning of the shearing, though it would  be permitted if offered at any time.  There is a debate regarding whether the first sheep sheared should be the one whose wool is shared.  Some believe that it should be done at the beginning, after five sheep have been sheared, but not at the end.

We learn from the Mishna that this law only applies to sheep.  There is no requisite amount of wool to be given, but the Sages ruled that it should be worth at least five sela in the area of Judea.

The rabbis discuss this mitzvah.  Rambam argues that because the kohanim did not receive their share in the land of Israel, we are all obligated to care for them.  That is why they receive teruma in bread, wine and meat and why they are given the zero'a, lechayayim, kevah and eat the Temple sacrifices.  Reishit HaGez provides their clothing.