Philip Schaff's Popular Commentary (4 vols)
Hebrews 7 - Introduction
Hebrews 7:1-28. Resuming his argument, the writer proceeds to show that Jesus, belonging as He did to the order of Melchisedec, is superior to Aaron. In proving his point he first (1) treats of the priest king Melchisedec with reference to the history of Genesis (14), dwells upon his greatness (Hebrews 7:1-3), and on his superiority to Abraham, the ancestor and representative of Levi (Hebrews 7:4-10); he then (2) treats of the prediction (Psalms 110), wherein it is foretold that a perpetual priest is to arise who is to supersede the Aaronic priests because of their inefficiency; shows (3) that the greater solemnity of the institution of the priesthood of Christ proves its superiority to the priesthood of Levi (Hebrews 7:20-22); (4) its permanence (Hebrews 7:23-25); and (5) its adaptedness to our needs (Hebrews 7:26-28).
Here begin the things hard to be explained; not that the difficulty lies in the phrases used concerning Melchisedec, for these, however startling to us, were familiar modes of expression among the Jews, but that the Jews were slow to receive and apply the general teaching of the passage. The Jewish priesthood had the highest sanctions; it was the divinest part of the law. The government was originally a theocracy; the priest was the representative of the invisible King, His minister, and the mediator between the nation and Himself. The kingship came later. It originated partly in popular feeling, and was at first even displeasing to God. That the Messiah should be King, the Son of David, and the occupant of his throne, was generally allowed; but that He was to be priest also, that He was to set aside the ancient law, was something more difficult to believe. The cessation of the priesthood is indeed as great a mystery to the Jews as the destruction of the Temple, and is in their view even more irremediable. And yet One is to arise after the order of Melchisedec, and not after that of Aaron, and is to hold uninterrupted office in His Church.