if only to teach warfare to the subsequent generations of Israel, especially to those who had not known it formerly:
We are here told what remained of the old inhabitants of Canaan. 1. There were some of them that kept together in united bodies, unbroken (Jdg 3:3): The five lords of the Philistines, namely, Ashdod, Gaza, Askelon, Gath, and Ekron, Sa1 6:17.
Commenting on Judges 3:1-7
Only that the generations of the children of Israel might know and teach them war,.... That is, the following nations were left in the land, that the young generations of Israel might by their wars and conflicts with them learn the art of war, and be inured to martial discipline; which, if none had been left to engage with, they had been ignorant of: besides...
Jdg 3:1-2 The reason, which has already been stated in Jdg 2:22, viz., “to prove Israel by them,” is still further elucidated here. In the first place (Jdg 3:1), את־ישׂראל is more precisely defined as signifying “all those who had not known all the wars of Canaan,” sc., from their own observation and experience, that is to say, the generation of the Israelites which rose...
Commenting on Judges 3:1-2