Judges 2:20-23

Then YAHWEH became furious with Israel, saying, “Because this nation has violated the covenant that I commanded their fathers to keep, and because they no longer listen to my voice, I will no longer drive out any of the nations that remained in the land after Joshua died.” Over and over YAHWEH tested Israel to see if they would faithfully walk in his ways, as their ancestors had done. So YAHWEH intentionally left pagan nations in the land instead of driving them all out at once, and he did not give Joshua the victory over them, nor did he drive them out after Joshua’s death.