as was the custom of the priesthood, he was chosen by lot to enter [the sanctuary of] the temple of the Lord and burn incense [on the altar of incense]. [Ex 30:7]
The sons of Amram: Aaron and Moses. Aaron was set apart to consecrate him as most holy, he and his sons forever, to burn incense before the Lord, attend to His service, and to bless [worshipers] in His name forever.
But [the line of] Aaron and his sons made offerings on the altar of burnt offering and on the altar of incense, ministering for all the work of the Holy of Holies (Most Holy Place), and [they did so] to make atonement for Israel, according to all that Moses, God’s servant, had commanded.
But when Uzziah became strong, he became so proud [of himself and his accomplishments] that he acted corruptly, and he was unfaithful and sinned against the Lord his God, for he went into the temple of the Lord to burn incense on the altar of incense. [Num 3:38]
My sons, do not be negligent and careless now, for the Lord has chosen you to stand in His presence, to attend to His service, and to be His ministers and burn incense.”
as a reminder to the sons of Israel so that no layman—that is, one who is not of the descendants of Aaron should approach to offer incense before the Lord; so that he will not become like Korah and as his company—just as the Lord had said to him through Moses.
Now when these things have been prepared in this way, the priests continually enter the outer [or first section of the] tabernacle [that is, the Holy Place] performing [their ritual acts of] the divine worship,
Moreover, I selected him out of all the tribes of Israel to be My priest, to go up to My altar, to burn incense, to wear an ephod before Me. And [from then on] I gave to the house of your father all the fire offerings of the sons of Israel.