These are the nations the LORD left to test all those Israelites who had not experienced any of the wars in Canaan
References for Judges 3:1
(he did this only to teach warfare to the descendants of the Israelites who had not had previous battle experience):
the five rulers of the Philistines, all the Canaanites, the Sidonians, and the Hivites living in the Lebanon mountains from Mount Baal Hermon to Lebo Hamath.
References for Judges 3:3
They were left to test the Israelites to see whether they would obey the LORD’s commands, which he had given their ancestors through Moses.
References for Judges 3:4
The Israelites lived among the Canaanites, Hittites, Amorites, Perizzites, Hivites and Jebusites.
References for Judges 3:5
They took their daughters in marriage and gave their own daughters to their sons, and served their gods.
References for Judges 3:6
The Israelites did evil in the eyes of the LORD; they forgot the LORD their God and served the Baals and the Asherahs.
References for Judges 3:7
The anger of the LORD burned against Israel so that he sold them into the hands of Cushan-Rishathaim king of Aram Naharaim, to whom the Israelites were subject for eight years.
References for Judges 3:8
But when they cried out to the LORD, he raised up for them a deliverer, Othniel son of Kenaz, Caleb’s younger brother, who saved them.
References for Judges 3:9
The Spirit of the LORD came on him, so that he became Israel’s judge and went to war. The LORD gave Cushan-Rishathaim king of Aram into the hands of Othniel, who overpowered him.
References for Judges 3:10