Aaron and his sons - shall wait on their priest's office - It was the business of the priests to offer the different sacrifices to God; to consecrate the shew-bread, pour out the libations, burn the incense, sprinkle the blood of the victims, and bless the people. In a word, they were the servants of God alone.

And thou shalt appoint Aaron and his sons,.... To the priestly office; this was done before, but is renewed for the confirmation of it, and repeated to put them in mind of it, that they be careful to execute it, as follows:

and they shall wait on their priest's office, to do what was peculiar to it, both in the holy and in the most holy place, at the altar, and within, the vail, where the Levites had nothing to do; and this is observed that the priests might take notice, that by the gift of the Levites to them, they were not excused from doing any part of service which was proper to them as priests; for they were given them that they might more readily attend their office, and be wholly employed in it; just as, under the Gospel dispensation, deacons were appointed to take care of the secular affairs of the church, that the apostles might give up themselves to the word of God and prayer, Acts 6:2,

and the stranger that cometh nigh shall be put to death; that comes nigh to perform any part of the priest's office peculiar to him as to offer sacrifice, burn incense, &c. whether he be a common Israelite, or even a Levite, as Korah was; any that was not a priest was reckoned a stranger, and so to be put to death for intruding into the office, as the above mentioned person was: so Aben Ezra interprets it of anyone that came nigh to a priest, to be with him or join with him in the execution of his office, whether an Israelite or a Levite, he shall die: the Targum of Jonathan adds, by flaming fire before the Lord.

Aaron and his sons were to be appointed by Moses to take charge of the priesthood; as no stranger, no one who was not a son of Aaron, could approach the sanctuary without being put to death (cf. Numbers 1:53 and Leviticus 22:10).

And thou shalt appoint Aaron and his sons, and they shall wait on their priest's office: and the {g} stranger that cometh nigh shall be put to death.

(g) Any that would minister not being a Levite.

3:10 The stranger - That is, every one who is of another family than Aaron's; yea, though he be a Levite. That cometh nigh - To execute any part of the priest's office.

3:1-13 There was much work belonging to the priests' office, and there were now only Aaron and his two sons to do it; God appoints the Levites to attend them. Those whom God finds work for, he will find help for. The Levites were taken instead of the first-born. When He that made us, saves us, as the first-born of Israel were saved, we are laid under further obligations to serve him faithfully. God's right to us by redemption, confirms the right he has to us by creation.