Here, I. The family of Aaron is confirmed in the priests' office, Num 3:10. They had been called to it before, and consecrated; here they are appointed to wait on their priests' office: the apostle uses this phrase (Rom 12:7), Let us wait on our ministry. The office of the ministry requires a constant attendance and great diligence; so frequent are the returns of its work, and yet so transient its favourable opportunities, that it must be waited on. Here is repeated what was said before (Num 1:51): The stranger that cometh nigh shall be put to death, which forbids the invading of the priest's office by any other person whatsoever; none must come nigh to minister but Aaron and his sons only, all others are strangers. It also lays a charge on the priests, as door-keepers in God's house, to take care that none should come near who were forbidden by the law; they must keep off all intruders, whose approach would be to the profanation of the holy things, telling them that if they came near it was at their peril, they would die by the hand of God, as Uzza did. The Jews say that afterwards there was hung over the door of the temple a golden sword (perhaps alluding to that flaming sword at the entrance of the garden of Eden), on which was engraven, The stranger that cometh nigh shall be put to death.

II.A particular account is given of this family of Aaron; what we have met with before concerning them is here repeated. 1. The consecration of the sons of Aaron, Num 3:3. They were all anointed to minister before the Lord, though it appeared afterwards, and God knew it, that two of them were wise and two were foolish. 2. The fall of the two elder (Num 3:4): they offered strange fire, and died for so doing, before the Lord. This is mentioned here in the preamble to the law concerning the priesthood, for a warning to all succeeding priests; let them know, by this example, that God is a jealous God, and will not be mocked; the holy anointing oil was an honour to the obedient, but not a shelter to the disobedient. It is here said, They had no children, Providence so ordering it, for their greater punishment, that none of their descendants should remain to be priests, and so bear up their name who had profaned God's name. 3. The continuance of the two younger: Eleazar and Ithamar ministered in the sight of Aaron. It intimates, (1.) The care they took about their ministration not to make any blunders; they kept under their father's eye, and took instruction from him in all they did, because, probably, Nadab and Abihu got out of their father's sight when they offered strange fire. Note, It is good for young people to act under the direction and inspection of those that are aged and experienced. (2.) The comfort Aaron took in it; it pleased him to see his younger sons behave themselves prudently and gravely, when his two elder had miscarried. Note, It is a great satisfaction to parents to see their children walk in the truth, Jo3 1:4.

III.A grant is made of the Levites to be assistants to the priests in their work: Give the Levites to Aaron, Num 3:9. Aaron was to have a greater propriety in, and power over, the tribe of Levi than any other of the prices had in and over their respective tribes. There was a great deal of work belonging to the priests' office, and there were now only three pairs of hands to do it all, Aaron's and his two sons'; for it does not appear that they had either of them any children at this time, at least not any that were of age to minister, therefore God appoints the Levites to attend upon them. Note, Those whom God finds work for his will find help for. Here is, 1. The service for which the Levites were designed: they were to minister to the priests in their ministration to the Lord (Num 3:6), and to keep Aaron's charge (Num 3:7), as the deacons to the bishops in the evangelical constitution, serving at tables, while the bishops waited on their ministry. The Levites killed the sacrifices, and then the priests needed only to sprinkle the blood and burn the fat: the Levites prepared the incense, the priests burnt it. They were to keep, not only Aaron's charge, but the charge of the whole congregation. Note, It is a great trust that is reposed in ministers, not only for the glory of Christ, but for the good of his church; so that they must not only keep the charge of the great high priest, but must also be faithful to the souls of men, in trust for whom a dispensation is committed to them. 2. the consideration upon which the Levites were demanded; they were taken instead of the first-born. The preservation of the first-born of Israel, when all the first-born of the Egyptians (with whom they were many of them mingled) were destroyed, was looked upon by him who never makes any unreasonable demands as cause sufficient of the appropriating of all the first-born thenceforward to himself (Num 3:13): All the first-born are mine. That was sufficient to make them his, though he had given no reason for it, for he is the sole fountain and Lord of all beings and powers; but because all obedience must flow from love, and acts of duty must be acts of gratitude, before they were challenged into peculiar services they were crowned with peculiar favours. Note, When he that made us saves us we are thereby laid under further obligations to serve him and live to him. God's right to us by redemption corroborates the right he has to us by creation. Now because the first-born of a family are generally the favourites, and some would think it a disparagement to have their eldest sons servants to the priests, and attending before the door of the tabernacle, God took the tribe of Levi entire for his own, in lieu of the first-born, Num 3:12. Note, God's institutions put no hardships upon men in any of their just interests or reasonable affections. It was presumed that the Israelites would rather part with the Levites than with the first-born, and therefore God graciously ordered the exchange; yet for us he spared not his own Son.

Because all the firstborn are mine,.... Not merely in a general way, as all creatures are his, but in a special manner as his own, and that for the following reason:

for on the day that I smote all the firstborn in the land of Egypt,

I hallowed unto me all the firstborn in Israel, both man and beast; that is, sanctified or set them apart as his own special property, or ordered the people of Israel so to do, Exo 13:2; for as when he destroyed the firstborn of the Egyptians, he saved the firstborn of Israel, he had a special claim upon them as his; and though it was in the night when he destroyed the firstborn of Egypt, yet it was the night which preceded that day, and was a part of that day, even the fifteenth of Nisan, when the instructions were given to sanctify all the firstborn; though, as Aben Ezra observes, "day" signifies "time", so that it was at or about the same time that the one and the other were done:

mine they shall be; this was declared when they were ordered to be sanctified to him, but now they were to be exchanged for the Levites:

I am the Lord; who have sovereign power to do as he would in claiming the firstborn, and then in exchanging them for the Levites, and appointing the Levites to minister to the priests, and serve in the tabernacle.

I have taken the Levites, &c.--The consecration of this tribe did not originate in the legislative wisdom of Moses, but in the special appointment of God, who chose them as substitutes for the first-born. By an appointment made in memory of the last solemn judgment on Egypt (from which the Israelitish households were miraculously exempt) all the first-born were consecrated to God (Exo 13:12; Exo 22:29), who thus, under peculiar circumstances, seemed to adopt the patriarchal usage of appointing the oldest to act as the priest of the family. But the privilege of redemption that was allowed the first-born opened the way for a change; and accordingly, on the full organization of the Mosaic economy, the administration of sacred things formerly committed to the first-born was transferred from them to the Levites, who received that honor partly as a tribute to Moses and Aaron, partly because this tribe had distinguished themselves by their zeal in the affair of the golden calf (Exo 32:29), and also because, being the smallest of the tribes, they could ill find suitable employment and support in the work. (See on Deu 33:8). The designation of a special class for the sacred offices of religion was a wise arrangement; for, on their settlement in Canaan, the people would be so occupied that they might not be at leisure to wait on the service of the sanctuary, and sacred things might, from various causes, fall into neglect. But the appointment of an entire tribe to the divine service ensured the regular performance of the rites of religion. The subsequent portion of the chapter relates to the formal substitution of this tribe.

I am the Lord--that is, I decree it to be so; and being possessed of sovereign authority, I expect full obedience.