Jamieson, Fausset and Brown on Leviticus 6:20

Le 6:19-23. The High Priest's Meat Offering.

20. This is the offering of Aaron, and of his sons--the daily meat offering of the high priest; for though his sons are mentioned along with him, it was probably only those of his descendants who succeeded him in that high office that are meant. It was to be offered, one half of it in the morning and the other half in the evening--being daily laid by the ministering priest on the altar of burnt offering, where, being dedicated to God, it was wholly consumed. This was designed to keep him and the other attendant priests in constant remembrance, that though they were typically expiating the sins of the people, their own persons and services could meet with acceptance only through faith, which required to be daily nourished and strengthened from above.