Hebrews Chapter 7 Verse 20(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:)

If therefore perfection were by the Levitical priesthood, (for under it the people received the law,) what further need [was there] that another priest should rise after the order of Melchisedec, and not be called after the order of Aaron?

For the priesthood being changed, there is made of necessity a change also of the law.

For he of whom these things are spoken pertaineth to another tribe, of which no man gave attendance at the altar.

For [it is] evident that our Lord sprang out of Juda; of which tribe Moses spake nothing concerning priesthood.

And it is yet far more evident: for that after the similitude of Melchisedec there ariseth another priest,

Who is made, not after the law of a carnal commandment, but after the power of an endless life.

For he testifieth, Thou [art] a priest for ever after the order of Melchisedec.

For there is verily a disannulling of the commandment going before for the weakness and unprofitableness thereof.

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]:

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:

But this [man], because he continueth ever, hath an unchangeable priesthood.

Wherefore he is able also to save them to the uttermost that come unto God by him, seeing he ever liveth to make intercession for them.

For such an high priest became us, [who is] holy, harmless, undefiled, separate from sinners, and made higher than the heavens;

Who needeth not daily, as those high priests, to offer up sacrifice, first for his own sins, and then for the people's: for this he did once, when he offered up himself.

For the law maketh men high priests which have infirmity; but the word of the oath, which was since the law, [maketh] the Son, who is consecrated for evermore.

Now of the things which we have spoken [this is] the sum: We have such an high priest, who is set on the right hand of the throne of the Majesty in the heavens;

A minister of the sanctuary, and of the true tabernacle, which the Lord pitched, and not man.

For every high priest is ordained to offer gifts and sacrifices: wherefore [it is] of necessity that this man have somewhat also to offer.

The Book of Hebrews, Chapter 7, Verse 20