Judges 2:21-23

21I also will not henceforth dispossess from before them any of the nations that Joshua left when he died; 22that through them I may prove Israel, whether they will keep the way of Jehovah to walk therein, as their fathers did keep [it], or not. 23Therefore Jehovah left those nations, without dispossessing them hastily, neither delivered he them into the hand of Joshua.