Hebrews 7:12-14

For when there is a change in the priesthood, there is of necessity a change of the law [concerning the priesthood] as well. For the One of whom these things are said belonged [not to the priestly line of Levi but] to another tribe, from which no one has officiated or served at the altar. For it is evident that our Lord descended from [the tribe of] Judah, and Moses mentioned nothing about priests in connection with that tribe.