Joshua 9:18-20

18The Israelites did not attack them, because of the promise that their leaders had made. They had made a strong promise in the name of the Lord God of Israel that they would not kill the Gibeonites. The Israelite people were angry with their leaders, because of the agreement.

19But all the leaders said to them, ‘We have made a strong promise to the Lord, Israel's God. So now we cannot hurt the Gibeonites.

20But this is what we will do. We will let them live, because we made a strong promise to do that. Then God will not punish us.