8 Yahweh spoke to Aaron, “I, behold, I have given you the command of my wave offerings, even all the holy things of the children of Israel; to you have I given them by reason of the anointing, and to your sons, as a portion forever. 9 This shall be your of the most holy things, reserved from the fire: every offering of theirs, even every meal offering of theirs, and every sin offering of theirs, and every trespass offering of theirs, which they shall render to me, shall be most holy for you and for your sons. 10 You shall eat of it like the most holy things. Every male shall eat of it. It shall be holy to you. 11 “This is yours, too: the wave offering of their gift, even all the wave offerings of the children of Israel. I have given them to you, and to your sons and to your daughters with you, as a portion forever. Everyone who is clean in your house shall eat of it. 12 “All the best of the oil, and all the best of the vintage, and of the grain, the first fruits of them which they give to Yahweh, to you have I given them. 13 The first-ripe fruits of all that is in their land, which they bring to Yahweh, shall be yours; everyone who is clean in your house shall eat of it. 14 “Everything devoted in Israel shall be yours. 15 Everything that opens the womb, of all flesh which they offer to Yahweh, both of man and animal shall be yours: nevertheless you shall surely redeem the firstborn of man, and you shall redeem the firstborn of unclean animals.

Matthew Henry's Commentary on Numbers 18:8-15

Commentary on Numbers 18:8-19

(Read Numbers 18:8-19)

All believers are spiritual priests, and God has promised to take care of them. Godliness has the promise of the life that now is. And from the provision here made for the priests, the apostle shows that it is the duty of christian churches to maintain their ministers. Scandalous maintenance makes scandalous ministers. The priests were to be wholly devoted to their ministry, not diverted from it, or disturbed in it, by worldly care or business. Also, that they might be examples of living by faith, not only in God's providence, but in his ordinances. The best should be offered for the first-fruits unto the Lord. Those who think to save, by putting God off with the refuse, deceive themselves, for God is not mocked.