Judges 3:1-4

Now these are the nations that the Lord left, to test Israel by them (that is, all the Israelites who had not experienced any of the wars of Canaan;

only in order that the generations of the sons of Israel might be taught war, those who had not experienced it previously).

These nations are: the five governors of the Philistines and all the Canaanites and the Sidonians, and the Hivites who lived on Mount Lebanon, from Mount Baal-hermon as far as Lebo-hamath.

They were left to test Israel by them, to find out if they would obey the commandments of the Lord, which He had commanded their fathers through Moses.