During Aaron’s first priestly work after the inauguration week of Lev 8, at one point Aaron’s sons “presented the blood to him.” The blood is the blood of the Sin Offering, the first offering Aaron makes in his official role as High Priest.
What is this about? During our study of Lev 1–7, we never read anything about other priests presenting blood. Why are Aaron’s sons holding blood?
The Mishnah may give us a clue. The Mishnah is a collection of oral tradition, written down a few centuries after Christ, but recording traditions that date before Jesus.
Mishnah Yoma records regulations about the Day of Atonement. In Yoma 3:4, it says, “He slaughtered [the bullock] and received its blood in a bason; and he gave it to one that should stir it up on the fourth terrace of the Sanctuary so that it should not congeal” (emphasis mine; taken from Herbert Danby’s translation; cf. 4:3 which also mentions stirring the blood).
Apparently, butchering the animal properly could take some time, long enough for the blood to begin congealing. It became one of the other priest’s job to collect the blood in the basin and stir it to avoid the blood thickening up before it was sprinkled upon the altar.
There are a lot of noble and ignoble positions of service in the local church, but I am really glad that “blood-stirrer” is no longer one of them!