John Calvin Commentary Hebrews 5:6

"as he saith also in another [place,] Thou art a priest for ever After the order of Melchizedek." — Hebrews 5:6 (ASV)

As he says in another place, or, elsewhere, etc. Here is expressed more clearly what the Apostle intended. This is a remarkable passage, and indeed the whole Psalm from which it is taken, for there is hardly anywhere a clearer prophecy concerning Christ’s eternal priesthood and His kingdom.

And yet the Jews try all means to evade it, to obscure the glory of Christ, but they cannot succeed. They apply it to David, as though he was the person whom God commanded to sit on His right hand; but this is an instance of extreme effrontery, for we know that it was not lawful for kings to exercise the priesthood.

On this account, Uzziah, that is, for the sole crime of meddling with an office that did not belong to him, so provoked God that he was struck with leprosy (2 Chronicles 26:18). It is therefore certain that neither David nor any one of the kings is intended here.

If they raise this objection and say that princes are sometimes called כהנים cohenim, priests, I indeed allow it, but I deny that the word can be so understood here. For the comparison made here leaves nothing doubtful: Melchizedek was God’s priest; and the Psalmist testifies that the king whom God has set on His right hand would be a kohen according to the order of Melchizedek.

Who does not see that this is to be understood of the priesthood? For as it was a rare and almost singular thing for the same person to be a priest and a king—at least an unusual thing among God’s people—therefore he presents Melchizedek as the type of the Messiah, as if he had said, “The royal dignity will not prevent him from exercising the priesthood also, for a type of such a thing has already been presented in Melchizedek.” And indeed all among the Jews who have any modesty have conceded that the Messiah is the person spoken of here, and that His priesthood is what is commended.

What is in Greek, κατὰ τάξιν according to the order, is in Hebrew, על-דברתי ol-deberti, and means the same. It may be rendered, “according to the way” or manner. This confirms what I have already said: that as it was an unusual thing among the people of God for the same person to hold the office of both a king and a priest, an ancient example was brought forward by which the Messiah was represented. The rest the Apostle himself will explain in more detail in what follows.