Psalms 110:4

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

God is not a man, that he should lie; neither the son of man, that he should repent: hath he said, and shall he not do it? or hath he spoken, and shall he not make it good?

As he saith also in another place, Thou art a priest for ever after the order of Melchisedec.

(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:) without...: or, without swearing of an oath

And Melchizedek king of Salem brought forth bread and wine: and he was the priest of the most high God.

Even he shall build the temple of the LORD; and he shall bear the glory, and shall sit and rule upon his throne; and he shall be a priest upon his throne: and the counsel of peace shall be between them both.

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. consecrated: Gr. perfected

For when God made promise to Abraham, because he could swear by no greater, he sware by himself, Saying, Surely blessing I will bless thee, and multiplying I will multiply thee. And so, after he had patiently endured, he obtained the promise. For men verily swear by the greater: and an oath for confirmation is to them an end of all strife. Wherein God, willing more abundantly to shew unto the heirs of promise the immutability of his counsel, confirmed it by an oath: confirmed...: Gr. interposed himself by That by two immutable things, in which it was impossible for God to lie, we might have a strong consolation, who have fled for refuge to lay hold upon the hope set before us:

Whither the forerunner is for us entered, even Jesus, made an high priest for ever after the order of Melchisedec.

And hath made us kings and priests unto God and his Father; to him be glory and dominion for ever and ever. Amen.

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?

The LORD hath sworn in truth unto David; he will not turn from it; Of the fruit of thy body will I set upon thy throne. body: Heb. belly