Contracts by Oaths

Stay in this land as a foreigner, and I will be with you and bless you. For I will give all these lands to you and your offspring, and I will confirm the oath that I swore to your father Abraham.

And they got up early the next morning and swore an oath to each other. Then Isaac sent them on their way, and they left him in peace.

And Joshua made a treaty of peace with them to let them live, and the leaders of the congregation swore an oath to them.

This is how we will treat them: We will let them live, so that no wrath will fall on us because of the oath we swore to them.”

…the covenant He made with Abraham, and the oath He swore to Isaac.

Men swear by someone greater than themselves, and their oath serves as a confirmation to end all argument.

So when God wanted to make the unchanging nature of His purpose very clear to the heirs of the promise, He guaranteed it with an oath.