John Calvin on Hebrews 7:20-22

20. And inasmuch as not without an oath, etc. Here is another argument, why the Law ought to give place to the Gospel; for God has set Christ’s priesthood above that of Aaron, since in honor to the former he was pleased to make an oath. For when he appointed the ancient priests, he introduced no oath; but it is said of Christ, the Lord swore; which was doubtless done for the sake of honoring him. We see the end for which he again quotes the Psalmist, even that we may know, that more honor through God’s oath was given to Christ than to any others. But we must bear in mind this truth, that a priest is made that he may be the surety of a covenant. The Apostle hence concludes, that the covenant which God has made by Christ with us, is far more excellent than the old covenant of which Moses was the interpreter.

Hebrews Chapter 7:23-28

23. And they truly were many priests, because they were not suffered to continue by reason of death:

23. Et illi quidem plures facti fuerunt sacerdotes, quod prohiberentur morti permanere:

24. But this man, because he continueth ever, hath an unchangeable priesthood.

24. Hic autem quia perpetuo manet immutabile habet sacerdotium.

25. Wherefore he is able also to save them to the uttermost that come unto God by him, seeing he ever liveth to make intercession for them.

25. Unde et servare in aeternum potest eos qui per ipsum Deo appropinquant, semper vivens ut intercedat pro nobis.

26. For such an high priest became us, who is holy, harmless, undefiled, separate from sinners, and made higher than the heavens;

26. Talis enim nos decebat Pontifex, sanctus, innocens, impollutus, segregatus a peccatoribus, et excelsior coelis factus;

27. Who needeth not daily, as those high priests, to offer up sacrifice, first for his own sins, and then for the people’s: for this he did once, when he offered up himself.

27. Qui non necesse habeat quotidie, quemadmodum sacerdotes, primum pro suis peccatis hostias offerre, deinde pro populi: hoc enim semel fecit, quum seipsum obtulit.

28. For the law maketh men high priests which have infirmity; but the word of the oath, which was since the law, maketh the Son, who is consecrated for evermore.

28. Lex quidem homines constituit sacerdotes habentes informatem; sermo autem jurisjurandi, quod lege posterius est, Filium in aeternum perfectum.