Verses 20-25 draw out the pastoral implications of the conclusion that the writer reached in verses 18-19.
7:20-21 Another oath from God (Ps. 110:4) launched Messiah's priesthood. The Levitical priesthood had no such origin, another indication of its inferiority.
7:22 Because God promised on oath to install Messiah permanently as our priest, the writer could say that Jesus is the guarantee of a better covenant. Since the old priesthood was the heart of the Old Covenant, and God terminated both of them, a new priesthood must accompany the New Covenant that is superior to the Old Covenant. Since the new Priest has come, so must the New Covenant have come (cf. Luke 22:20). This is the first mention in the epistle of the word "covenant"that will play a major role in the writer's argument to follow.
"Hebrews develops the theme of the new covenant more fully than any other NT writer, the epistle accounting for just over half the occurrences of diathekein the NT."224
