Hebrews 5:4-5
And no one takes this honor to himself, but he that is called by God, as Aaron also was called.
Hebrews 5:10
being called by God a high priest after the order of Melchisedec.
Hebrews 7:11-14
If, then, there had been a perfect expiation by means of the Levitical priesthood, (for with reference to it, the people received the law,) what further need was there that another priest should be raised up after the order of Melchisedec, and not be called after the order of Aaron?
Hebrews 7:23-28
And those priests, indeed, have been many, because they were prevented by death from continuing in office.