Joshua 21:43
And the LORD gave unto Israel all the land which he sware to give unto their fathers; and they possessed it, and dwelt therein. And the LORD gave unto Israel all the land which he sware to give unto their fathers; and they possessed it, and dwelt therein.
The Lord faithfully kept His sworn promise to the fathers by giving Israel all the land to possess and to dwell in. After the power of Canaan had been broken, Joshua divided the given territory and allotted it to the tribes. God's own law was made the law of the land Israel received.
Continued possession was conditioned on obedient trust, requiring Israel to trust God and finish driving out the inhabitants instead of making leagues with the Canaanites, and failure in this broke the condition of obedience attached to holding Canaan. Satan was determined to keep his hold on Canaan, and once it became Israel's home he hated Israel with cruel and malignant hatred and plotted their destruction. Working through evil spirits he brought strange gods among them, and because Israel broke God's law they were finally scattered from the land of promise.