Hebrews 7:19-23

For the law made nothing perfect, but the bringing in of a better hope did; by the which we draw nigh unto God.

And inasmuch as not without an oath he was made priest:

(For those priests were made without an oath; but this with an oath by him that said unto him, The Lord sware and will not repent, Thou art a priest for ever after the order of Melchisedec:)

By so much was Jesus made a surety of a better testament.

And they truly were many priests, because they were not suffered to continue by reason of death: