Hebrews 5:1-6

For every high priest taken from among men is appointed on behalf of men in things pertaining to God, in order to offer both gifts and sacrifices for sins; he can deal gently with the ignorant and misguided, since he himself also is beset with weakness; and because of it he is obligated to offer sacrifices for sins, as for the people, so also for himself. And no one takes the honor to himself, but receives it when he is called by God, even as Aaron was. So also Christ did not glorify Himself so as to become a high priest, but He who said to Him, “YOU ARE MY SON, TODAY I HAVE BEGOTTEN YOU”; just as He says also in another passage, “YOU ARE A PRIEST FOREVER ACCORDING TO THE ORDER OF MELCHIZEDEK.”