Joshua 9:18 KJV

16And it came to pass at the end of three days after they had made a league with them, that they heard that they were their neighbours, and that they dwelt among them.

17And the children of Israel journeyed, and came unto their cities on the third day. Now their cities were Gibeon, and Chephirah, and Beeroth, and Kirjathjearim.

18And the children of Israel smote them not, because the princes of the congregation had sworn unto them by the LORD God of Israel. And all the congregation murmured against the princes.

19But all the princes said unto all the congregation, We have sworn unto them by the LORD God of Israel: now therefore we may not touch them.

20This we will do to them; we will even let them live, lest wrath be upon us, because of the oath which we sware unto them.