Judges 3:2
“Only that the generations of the children of Israel might know, to teach them war, at the least such as before knew nothing thereof;”
Now these are the nations which the Lord 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 before knew nothing thereof;
Namely, 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 entering in of Hamath.
And they were to prove Israel by them, to know whether they would hearken unto the commandments of the Lord, which he commanded their fathers by the hand of Moses.
Counter-Arguments
The strongest case that this verse does not belong in this theme.

Related Verses
“Now these are the nations which the Lord left, to prove Israel by them, even as many of Israel as had not known all the wars of Canaan;”
“And also all that generation were gathered unto their fathers: and there arose another generation after them, which knew not the Lord, nor yet the works which he had done for Israel.”
“And they were to prove Israel by them, to know whether they would hearken unto the commandments of the Lord, which he commanded their fathers by the hand of Moses.”
“That through them I may prove Israel, whether they will keep the way of the Lord to walk therein, as their fathers did keep it, or not.”
“And it came to pass in process of time, that the children of Ammon made war against Israel.”