Hebrews 5:10

προσαγορευθεὶς … Μελχισεδέκ “styled by God High Priest after the order of Melchizedek”. “ προσαγορεύειν expresses the formal and solemn ascription of the title to Him to whom it belongs (‘addressed as,' ‘styled')” (Westcott). “When the Son ascended and appeared in the sanctuary on High, God saluted Him or addressed Him as an High Priest after the order of Melchizedek, and, of course, in virtue of such an address constituted Him such an High Priest” (Davidson). Originally called to the priesthood by the words of Psalms 110, He is now by His resurrection and ascension declared to be perfectly consecrated and so installed as High Priest after the order of Melchizedek. It may be doubted, however, whether the full meaning of προσαγορεύειν “address” should here be found. The commoner meaning in writers of the time is “named” or “called”. Thus in Plutarch's Pericles, iv. 4, Anaxagoras, ὃν Νοῦν προσηγόρευον, xxvii. 2, λευκὴν ἡμέραν ἐκείνην προσαγ., xxiv. 6, of Aspasia, Ηρα προσαγορεύεται. and viii. 2 of Pericles himself, Ὀλύμπιον … προσαγορευθῆναι. So in Diod. Sic., i. 51, of the Egyptians, τάφους ἀϊδίους οἴκους προσαγορεύουσιν. It cannot be certainly concluded either from the tense or the context that this “naming” is to be assigned to the date of the ascension and not to the original appointment. The emphasis is on the words ὑπὸ τοῦ θεοῦ, not by man but by God has Christ been named High Priest; and on κατὰ … Μελχ. as warranting αἰωνίου.

The passage Hebrews 5:11 to Hebrews 6:20 is a digression occasioned by the writer's reflection that his argument from the priesthood of Melchizedek may be too difficult for his hearers. In order to stimulate attention he chides and warns them, pointing out the danger of backwardness. He justifies, however, his delivery of difficult doctrine notwithstanding their sluggishness, and this on two grounds: (1) because to lay again the foundations after men have once known them is useless (Hebrews 6:1-8); and (2) because he cannot but believe that his readers are after all in scarcely so desperate a condition. They need to have their hope renewed. This hope they have every reason to cherish, seeing that their fathers have already entered into the enjoyment of it, that God who cannot lie has sworn to the fulfilment of the promises, and that Jesus has entered the heavenly world as their forerunner.