Joshua 9:19-21

But 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. This 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. And the princes said unto them, Let them live; but let them be hewers of wood and drawers of water unto all the congregation; as the princes had promised them.