Once a year Aaron must make the altar ready for service to God by putting blood on its corners—the blood of the animal offered to remove sins. He is to do this once a year from now on. This altar belongs completely to the Lord’s service.”
Aaron’s sons Nadab and Abihu took their pans for burning incense, put fire in them, and added incense; but they did not use the special fire Moses had commanded them to use in the presence of the Lord.