Hebrews 7:21
(For those priests were made without an oath; but this with an oath, by him that said to him, The Lord swore, and will not repent, Thou art a priest for ever after the order of Melchisedec:)
Psalm 110:4
The LORD hath sworn, and will not repent, Thou art a priest for ever after the order of Melchisedek.
Hebrews 7:17
For he testifieth, Thou art a priest for ever after the order of Melchisedec.
1 Samuel 15:29
And also the Strength of Israel will not lie nor repent: for he is not a man, that he should repent.
Hebrews 6:16-18
For men verily swear by the greater: and an oath for confirmation is to them an end of all contradiction.