1 For every high priest taken from among men is ordained for men in things pertaining to God so that he may offer both gifts and sacrifices for sins. 2 He can have compassion on the ignorant and on those who are out of the way, for he himself also is compassed with infirmity. 3 And by reason of this he ought, as for the people, so also for himself, to offer for sins. 4 And no man takes this honor to himself, but he who is called by God, as was Aaron.
5 So also Christ did not glorify himself to be made a high priest, but it was he who said to him, "You are my Son. Today I have begotten you,"
6 As he also says in another place, "You are a priest forever after the order of Melchisedec."
7 He, in the days of his flesh, when he had offered up prayers and supplications with strong crying and tears to him who was able to save him from death, was heard because of his reverence. 8 Though he was a Son, yet he learned obedience by the things which he suffered. 9 And being made perfect, he became the author of eternal salvation to all those who obey him, 10 Called by God a high priest after the order of Melchisedec.
11 Concerning him, we have many things to say, and hard of interpretation, seeing you have become dull of hearing. 12 For when by the time you ought to be teachers, you have need of someone to teach you again what are the first principles of the oracles of God, and have become those who have need of milk and not of strong food. 13 For everyone who partakes of milk is unskillful in the word of righteousness, for he is a baby. 14 But strong food belongs to those who are of full age, even those who by reason of use have their senses exercised to discern both good and evil.
[v.5] - Quoting Psalm 2:7 (LXX).
[v.6] - Quoting Psalm 110:4 (LXX). Refer to Genesis 14:18-20 for the story of Melchisedec.