Charles Ellicott Commentary Hebrews 7:5

"And they indeed of the sons of Levi that receive the priest`s office have commandment to take tithes of the people according to the law, that is, of their brethren, though these have come out of the loins of Abraham:" — Hebrews 7:5 (ASV)

Those who are of the sons.—Rather, those of the sons of Levi who receive, etc. There is an apparent difficulty here. The priests, it is argued, did not receive tithes from the people; the tithe was paid to the Levites, and only the tenth part of this tithe went to the priests.

Two considerations seem to remove this difficulty entirely:

1. The question is not one of financial gain, but of position. The authority to exact tithes was, strictly speaking, vested in the priests, the supreme guardians of the laws relating to all religious duties and observances, and the Levites were only their assistants. That the priests received for their own use only a part of the tribute paid by the nation is not important here.
2. The Levites themselves paid tithes to the priests, who therefore stood alone in receiving tithes but paying none themselves. It is the positive ordinance of the law, and only this, that raises brothers above brothers and gives the priest this claim upon men who would otherwise be equal with him through common descent from Abraham.