'Take an Oath' in the Bible

And the Lord will give the knowledge of himself to Egypt, and the Egyptians will give honour to the Lord in that day; they will give him worship with offerings and meal offerings, and will take an oath to the Lord and give effect to it.

I have sworn by myself, the word has gone out of my mouth in righteousness, and will not return, that to me every knee shall bow, every tongue shall take an oath.