Charles Ellicott Commentary Leviticus 8:31

"And Moses said unto Aaron and to his sons, Boil the flesh at the door of the tent of meeting: and there eat it and the bread that is in the basket of consecration, as I commanded, saying, Aaron and his sons shall eat it." — Leviticus 8:31 (ASV)

And Moses said ... boil the flesh.—This refers to the ram of consecration. With the exception of the fat parts and the right shoulder, which were burned upon the altar, and the wave-breast, which was awarded to Moses as the officiating priest on this occasion (see Leviticus 8:8, and Exodus 29:31-32), the flesh of the victim is to be prepared by Aaron and his sons for the sacrificial meal (see Leviticus 7:11 and following).

From the peculiar nature of this offering, however, it is ordained that the flesh is to be boiled at the entrance of the tent of meeting, not at the door of the tabernacle of the congregation, as the Authorized Version states. According to Exodus 29:31, this is to take place in the holy place, that is, in the court, and is to be eaten with unleavened bread, thus distinguishing it from the ordinary sacrificial meal of the peace offering.

Aaron and his sons shall eat it.—This is another distinguishing feature of the sacrifice in question. While for ordinary sacrificial feasts the offerer could invite his family and strangers , with this particular sacrifice, no layman or non-priest could partake of the meal, because the flesh and the bread were peculiarly holy , as this sacrifice had the same atoning virtue as the burnt offering .