The priest's service is called a warfare; and who goes a warfare at his own charges? As they were well employed, so they were well provided for, and well paid. None shall serve God for nought. All believers are spiritual priests, and God has promised to take care of them; they shall dwell in the land, and verily they shall be fed, and shall not want any good thing. Godliness has the promise of the life that now is. And from this plentiful provision here made for the priests the apostle infers that it is the duty of Christian churches to maintain their ministers; those that served at the altar lived upon the altar. So those that preach the gospel should live upon the gospel, and live comfortably, Co1 9:13, Co1 9:14. Scandalous maintenance makes scandalous ministers. Now observe, 1. That much of the provision that was made for them arose out of the sacrifices which they themselves were employed to offer. They had the skins of almost all the sacrifices, which they might sell, and they had a considerable share out of the meat-offerings, sin-offerings, etc. Those that had the charge of the offerings had the benefit, Num 18:8. Note, God's work is its own wages, and his service carries its recompence along with it. Even in keeping God's commandments there is great reward. The present pleasures of religion are part of its pay. 2. That they had not only a good table kept for them, but money likewise in their pockets for the redemption of the first-born, and those firstlings of cattle which might not be offered in sacrifice. Thus their maintenance was such as left them altogether disentangled from the affairs of this life; they had no grounds to occupy, no land to till, no vineyards to dress, no cattle to tend, no visible estate to take care of, and yet had a more plentiful income than any other families whatsoever. Thus God ordered it that they might be the more entirely addicted to their ministry, and not diverted from it, nor disturbed in it, by any worldly care or business (the ministry requires a whole man); and that they might be examples of living by faith, not only in God's providence, but in his ordinance. They lived from hand to mouth, that they might learn to take no thought for the morrow; sufficient for the day would be the provision thereof: and they had no estates to leave their children, that they might by faith leave their children, that they might by faith leave them to the care of that God who had fed them all their lives long. 3. Of the provision that was made for their tables some is said to be most holy (Num 18:9, Num 18:10), which was to be eaten by the priests themselves, and in the court of the tabernacle only; but other perquisites were less holy, of which their families might eat, at their own houses, provided they were clean, Num 18:11-13. See Lev 21:10, etc. 4. It is commanded that the best of the oil, and the best of the wine and wheat, should be offered for the first-fruits unto the Lord, which the priest were to have, Num 18:12. Note, We must always serve and honour God with the best we have, for he is the best, and best deserves it; he is the first, and therefore must have the first ripe. Those that think to save charges by putting God off with the refuse do but deceive themselves, for God is not mocked. 5. All this is given to the priests by reason of the anointing, Num 18:8. It was not for the sake of their personal merits above other Israelites that they had these tributes paid to them, be it known unto them; but purely for the sake of the office to which they were anointed. Thus all the comforts that are given to the Lord's people are given them by reason of the anointing which they have received. It is said to be given them by an ordinance for ever (Num 18:8), and it is a covenant of salt for ever, Num 18:19. As long as the priesthood should continue this should continue to be the maintenance of it, that this lamp might not go out for want of oil to keep it burning. Thus provision is made that a gospel ministry should continue till Christ comes, by an ordinance for ever. Lo, I am with you (that is their maintenance and support) always, even to the end of the world. Thanks be to the Redeemer, it is the word which he has commanded to a thousand generations.

But the firstling of a cow, or the firstling of a sheep, or the firstling of a goat, thou shalt not redeem,.... That is, shalt not take the redemption price for them, but the creatures themselves; which they, the priests, were to take for their own use:

they are holy; separated to the Lord, and therefore not to be used in common by men, but were sacred to the Lord, or became the property of his priests; see Deu 15:19; how they were to be made use of follows:

thou shalt sprinkle their blood upon the altar; for they were to be sacrificed, and their blood used as in other sacrifices:

and shalt burn their fat for an offering made by fire; for a sweet savour unto the Lord; as the fat of other sacrifices was, and particularly of the peace offerings, which were wholly eaten otherwise, Lev 7:31.

Every thing devoted in Israel shall be thine--provided it was adapted for food or consumable by use; for the gold and silver vessels that were dedicated as the spoils of victory were not given to the priests, but for the use and adornment of the sacred edifice.