Hebrews 5:4-5
Again no one takes this honorable office for himself, but he is called by God, just as Aaron was.
Hebrews 5:10
while God himself pronounced him High Priest according to the order of Melchizedek.
Hebrews 7:11-14
Now if there were perfection through the Levitical priesthood, (and it was under it that the people received the Law) why was it still necessary for another kind of priest to arise, after the order of Melchizedek, instead of being reckoned according to the order of Aaron?
Hebrews 7:23-28
And they indeed have been made priests, many in number, because they have been prevented by death from continuing;