This honor - Την τιμην undoubtedly signifies here the office, which is one meaning of the word in the best Greek writers. It is here an honorable office, because the man is the high priest of God, and is appointed by God himself to that office.
But he that is called of God, as was Aaron - God himself appointed the tribe and family out of which the high priest was to be taken, and Aaron and his sons were expressly chosen by God to fill the office of the high priesthood. As God alone had the right to appoint his own priest for the Jewish nation, and man had no authority here; so God alone could provide and appoint a high priest for the whole human race. Aaron was thus appointed for the Jewish people; Christ, for all mankind.
Some make this "an argument for the uninterrupted succession of popes and their bishops in the Church, who alone have the authority to ordain for the sacerdotal office; and whosoever is not thus appointed is, with them, illegitimate." It is idle to employ time in proving that there is no such thing as an uninterrupted succession of this kind; it does not exist, it never did exist. It is a silly fable, invented by ecclesiastical tyrants, and supported by clerical coxcombs. But were it even true, it has nothing to do with the text. It speaks merely of the appointment of a high priest, the succession to be preserved in the tribe of Levi, and in the family of Aaron. But even this succession was interrupted and broken, and the office itself was to cease on the coming of Christ, after whom there could be no high priest; nor can Christ have any successor, and therefore he is said to be a priest for ever, for he ever liveth the intercessor and sacrifice for mankind. The verse, therefore, has nothing to do with the clerical office, with preaching God's holy word, or administering the sacraments; and those who quote it in this way show how little they understand the Scriptures, and how ignorant they are of the nature of their own office.
And no man taketh this honor to himself - No one has a right to enter on this office unless he has the qualifications which God has prescribed. There were fixed and definite laws in regard to the succession in the office of the high priest, and to the qualifications of him who should hold the office.
But he that is called of God as was Aaron - Aaron was designated by name. It was necessary that his successors should have as clear evidence that they were called of God to the office, as though they had been mentioned by name. The manner in which the high priest was to succeed to the office was designated in the Law of Moses, but in the time of Paul these rules were little regarded. The office had become venal, and was conferred at pleasure by the Roman rulers. Still it was true that according to the Law, to which alone Paul here refers, no one might hold this office but he who had the qualifications which Moses prescribed, and which showed that he was called of God. We may remark here:
(1) that this does not refer so much to an internal, as to an “external” call. He was to have the qualifications prescribed in the Law - but it is not specified that he should be conscious of an internal call to the office, or be influenced by the Holy Spirit to it. Such a call was, doubtless, in the highest degree desirable, but it was not prescribed as an essential qualification.
(2) this has no reference to the call to the work of the Christian ministry, and should not be applied to it. It should not be urged as a proof-text to show that a minister of the gospel should have a “call” directly from God, or that he should be called according to a certain order of succession. The object of Paul is not to state this - whatever may be the truth on this point. His object is, to show that the Jewish high priest was called of God to “his” office in a certain way, showing that he held the appointment from God, and that “therefore” it was necessary that the Great High Priest of the Christian profession should be called in a similar manner. To this alone the comparison should be understood as applicable.