And the LORD spoke to Moses, saying, “Charge Aaron and his sons, saying, ‘This is the teaching of the burnt offering. Rashi explains that the word charge is an expression of encouragement that the Bible uses when there is a cost. The commentators struggle with this explanation. The priests – Aaron and his descendants – don’t pay for the sacrifices, it’s the individual Israelite who must pay. So what cost is there to the priest? Maharal explains that it’s the priest’s “opportunity cost” – if he was not dealing with the sacrifice, he could be doing something to benefit himself. Indeed, every volunteer who works on behalf of the community is a priest and deserves our encouragement.