Hebrews 7:11-14

11Now if perfection had been attainable through the Levitical priesthood (for under it the people received the law), what further need would there have been for another priest to arise after the order of Melchizedek, rather than one named after the order of Aaron? 12For when there is a change in the priesthood, there is necessarily a change in the law as well. 13For the one of whom these things are spoken belonged to another tribe, from which no one has ever served at the altar. 14For it is evident that our Lord was descended from Judah, and in connection with that tribe Moses said nothing about priests.