Joshua 9:18-20 NIV

[18] But the Israelites did not attack them, because the leaders of the assembly had sworn an oath to them by the LORD, the God of Israel. The whole assembly grumbled against the leaders, [19] but all the leaders answered, “We have given them our oath by the LORD, the God of Israel, and we cannot touch them now. [20] This is what we will do to them: We will let them live, so that God’s wrath will not fall on us for breaking the oath we swore to them.”