Deuteronomy 18:1

1.The priests, the Levites, and all the tribe of Levi. This chapter contains three principal heads; for first, God shews that there was no reason why the Israelites should be aggrieved at paying tithes to the Levites, and at remitting the first-fruits and other oblations to the priests, since this tribe was deprived of their inheritance. Secondly, He obviates all quarrels, and prevents unlawful gains and pilferings, by assigning their just share to the priests and Levites. Thirdly, He defines how the oblations should be parted among them, and what part of the victims the priests were to take. As to the first clause, since God was as it were the lot of their inheritance, they justly claimed to themselves the right which he had transferred to them. If it were disagreeable to the people that their revenue should be tithed, God came as it were between, and declaring that it was His property in His right as King, appointed the Levites to be His stewards and collectors for receiving it. There was then no ground for any one to raise a dispute, unless he chose professedly to rob God. But this declaration often occurs; since it was of great importance that the people should be assured that God accounted as received by Himself what He had assigned to the Levites; not. only lest any portion should be withheld from them, but also that every one should willingly pay the lawful dues of God’s ministers; and again, lest any should wickedly murmur because the first-fruits and some portion of the sacrifices were appropriated for the subsistence of the priests. Another reason is also expressed, why the honor assigned to the priests should be paid without grudging; viz., because God had appointed them to be the ministers of His service; but “the laborer is worthy of his hire."