John Calvin Commentary Hebrews 7:12

"For the priesthood being changed, there is made of necessity a change also of the law." — Hebrews 7:12 (ASV)

For the priesthood being changed, or, transferred, etc. Since the authority of the Law and the priesthood is the same, Christ became not only a priest but also a Lawgiver, so that the right of Aaron, as well as of Moses, was transferred to him.

The sum of the whole is that the ministry of Moses was no less temporary than that of Aaron, and therefore both were annulled by the coming of Christ, for the one could not stand without the other.

By the word Law, we understand what specifically belonged to Moses. For the Law contains the rule of life and the gracious covenant of life, and in it we find everywhere many remarkable statements that instruct us in faith and in the fear of God. None of these aspects were abolished by Christ, but only that part which concerned the ancient priesthood.

For Christ is here compared with Moses. Therefore, whatever they had in common is not to be taken into account, but only the things in which they differ. They both offer God’s mercy to us, prescribe the rule of a holy and godly life, teach us the true worship of God, and exhort us to exercise faith and patience, and all the duties of godliness.

But Moses was different from Christ in this respect: while the love of the Gospel was not yet made known, he kept the people under veils, set forth the knowledge of Christ by types and shadows, and, in short, accommodated himself to the capacity of uninformed people, and did not rise higher than to basic elements.

We must remember, then, that the Law is that part of the ministry which was uniquely Moses' own and different from that of Christ. That law, as it was subordinate to the ancient priesthood, was abolished when the priesthood was abolished. And Christ, being made a priest, was also invested with the authority of a legislator, so that he might be the teacher and interpreter of the new covenant.

At the same time, the word Law is applied, though not in its strict sense, to the Gospel. But this less strict application of the term is far from being harsh; on the contrary, because of the contrast, it adds beauty to the sentence, as we find in Romans 7.

Moreover, the Pope's impiety is extremely arrogant, for he has inserted this article in his decretals: that he himself is now invested with the same authority Aaron formerly had, because the Law and the priesthood have supposedly been transferred to him.

We see what the Apostle says: he maintains that ceremonies have ceased since Christ came forth with the command to proclaim the new covenant.

It is absurd, therefore, to conclude from this that anything has been transferred to the ministers of Christ, for Christ himself alone is contrasted here with Moses and Aaron. Under what pretext, then, can Antichrist arrogate to himself any such authority?

I am not speaking now, indeed, for the sake of disproving such gross arrogance, but it is worthwhile to remind readers of this sacrilegious audacity, so that they may know that this notorious servant of the servants of Christ completely disregards the honor of his Master and boldly mangles the Scriptures, so that he may have some cloak for his own tyranny.