John Calvin 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)

And verily they, etc. It would be more suitable to render the words as follows: “because they are the sons of Levi.” The Apostle indeed does not say that the reason they received tithes was because they were the sons of Levi; instead, he is comparing the whole tribe with Melchizedek in this way.

Although God granted the Levites the right to require tithes from the people, and thus set them above all the Israelites, they have all descended from the same parent. Abraham, the father of them all, paid tithes to a priest of another race; therefore, all the descendants of Abraham are inferior to this priest.

Thus, the right conferred on the Levites was particular concerning the rest of their brothers; yet Melchizedek, without exception, occupies the highest place, so that all are inferior to him.

Some think that the tenths of tenths are intended—those which the Levites paid to the higher priests—but there is no reason to confine the general declaration in this way. The view, then, I have given is the most probable.