Numbers 33:52-55

33:52 you must drive out all the inhabitants of the land before you. Destroy all their carved images, all their molten images, and demolish their high places. 33:53 You must dispossess the inhabitants of the land and live in it, for I have given you the land to possess it. 33:54 You must divide the land by lot for an inheritance among your families. To a larger group you must give a larger inheritance, and to a smaller group you must give a smaller inheritance. Everyone’s inheritance must be in the place where his lot falls. You must inherit according to your ancestral tribes. 33:55 But if you do not drive out the inhabitants of the land before you, then those whom you allow to remain will be irritants in your eyes and thorns in your side, and will cause you trouble in the land where you will be living.

Deuteronomy 7:1-2

The Dispossession of Nonvassals

7:1 When the Lord your God brings you to the land that you are going to occupy and forces out many nations before you – Hittites, Girgashites, Amorites, Canaanites, Perizzites, Hivites, and Jebusites, seven nations more numerous and powerful than you – 7:2 and he delivers them over to you and you attack them, you must utterly annihilate them. Make no treaty with them and show them no mercy!