Joshua 21:43

Pass. How then did the Chanaanites keep possession of so many places? St. Augustine (q. 21,) answers, that they were suffered to do it for the "utility and trial" of the Israelites. For the latter were not sufficiently numerous at first to cultivate all the land. God had therefore promised that the nations should not be driven out all at once, lest the country should fall a prey to wild beasts, Exodus xxiii. 29. (Masius) --- During the life-time of Josue, none of them durst make head against him; and if many of the tribes did not take possession of all their cities, it was owing to their own negligence. After this hero was no more, the natives took courage, and greatly harassed the Israelites; but it is plain that the latter were not straitened for room, while Josue lived, since they invited the other tribes east of the Jordan to come and reside with them on the west, if they thought proper, chap. xvii. 19. (Calmet)