Judges 3:1-4

Now these are the nations which Jehovah left, to prove Israel by them, even as many of Israel as had not known all the wars of Canaan; only that the generations of the children of Israel might know, to teach them war, at the least such as beforetime knew nothing thereof: namely, the five lords of the Philistines, and all the Canaanites, and the Sidonians, and the Hivites that dwelt in mount Lebanon, from mount Baal-hermon unto the entrance of Hamath. And they were left, to prove Israel by them, to know whether they would hearken unto the commandments of Jehovah, which he commanded their fathers by Moses.