'Sworn' in the Bible

So then, because he was a prophet and knew that God had sworn to him with an oath to seat one of his descendants on his throne,

And since this was not done without a sworn affirmation -- for the others have become priests without a sworn affirmation,

but Jesus did so with a sworn affirmation by the one who said to him, "The Lord has sworn and will not change his mind, 'You are a priest forever'" --