Hebrews 7:5

And they indeed of the sons of Levi that receive the priest's office have commanded 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.

Hewitt sheds light on a supposed difficulty arising from the fact that the priests did not take tithes directly from the people, but from the Levites who in turn had taken them from the people; but, as he noted, that is going out of the way to find a difficulty. He wrote,

The usual procedure was for the Levites to take tithes, and the priests took a tithe of that tithe. If the priests took tithes from the people through the Levites, they were in actual fact taking tithes from the people. There is no need therefore to alter PEOPLE ([@laon]) into LEVI (@Leuin) as some have done in order to overcome a supposed difficulty.[9]

The big point in this verse is crystal clear, namely, that the Levites themselves in the person of their distinguished ancestor, Abraham, had themselves paid tithes to Melchizedek, thus making their priesthood inferior to his.

"Loins" is the ancient idiomatic name for the reproductive organs of man, being derived, oddly enough, from "kidneys," since the kidneys were once thought to be involved in reproduction. Milligan summed up the thought regarding the Levites and Melchizedek thus, "Throughout, it is implied Melchizedek was greater than Levi, then "a fortiori" Christ was (greater than Levi), of whom Melchizedek was a partial type."[10]

[9] Thomas Hewitt, The Epistle to the Hebrews (Grand Rapids, Michigan: Wm. B. Eerdmans Publishing Company, 1960), p. 118.

[10] Brooke Foss Westcott, op. cit., p. 179.