that by them I may prove Israel, whether they will keep the way of Yahweh to walk therein, as their fathers did keep it, or not.
So the anger of the LORD was hot against Israel; he said, Because the people had transgressed my covenant which I commanded their fathers, they have not hearkened to my voice; I will not henceforth drive out any from before them of the nations which Joshua left when he died: That through them I may prove Israel, whether they will keep the way for the LORD or not. Therefore the LORD left those nations, without driving them out ( Judges 2:20-23 ). "