John Calvin Commentary Hebrews 5:9

"and having been made perfect, he became unto all them that obey him the author of eternal salvation;" — Hebrews 5:9 (ASV)

And being made perfect, or sanctified, etc. This refers to the ultimate or more distant purpose, as it is called, why it was necessary for Christ to suffer: it was so that he might in this way become initiated into his priesthood. It is as if the Apostle had said that enduring the cross and death was for Christ a solemn kind of consecration, by which he indicates that all his sufferings related to our salvation. From this it follows that they are so far from being detrimental to his dignity that they are, on the contrary, his glory. For if salvation is highly esteemed by us, how honorably should we think of its cause or author? For he is not speaking here of Christ only as an example, but he ascends higher, stating that he by his obedience has blotted out our transgressions. He then became the cause of salvation because he obtained righteousness for us before God, having removed the disobedience of Adam by an act of an opposite kind—namely, obedience.

Sanctified suits the passage better than “made perfect.” The Greek word τελειωθεὶς means both; but as he speaks here of the priesthood, he fittingly mentions sanctification. And so Christ himself speaks in another place, “For their sakes I sanctify myself” (John 17:19). From this it appears that this is properly applied to his human nature, in which he performed the office of a priest, and in which he also suffered.

To all them that obey him. If, then, we desire that Christ’s obedience should be profitable to us, we must imitate him; for the Apostle means that its benefit will come only to those who obey. But by saying this he recommends faith to us, for he does not become ours, nor do his blessings, except to the extent that we receive them and him by faith. He seems at the same time to have adopted a universal term, all, for this purpose: to show that no one is excluded from salvation who is only teachable and becomes obedient to the Gospel of Christ.