Hebrews 7:4, 8, 13, 15, 18

Just think how great he was: Even the patriarch Abraham gave him a tenth of the plunder!

In the one case, the tenth is collected by people who die; but in the other case, by him who is declared to be living.

He of whom these things are said belonged to a different tribe, and no one from that tribe has ever served at the altar.

And what we have said is even more clear if another priest like Melchizedek appears

The former regulation is set aside because it was weak and useless