Exodus 23:29-31

I will not drive them out before you in a single year, that the land may not become desolate and the beasts of the field become too numerous for you. I will drive them out before you little by little, until you become fruitful and take possession of the land. I will fix your boundary from the Red Sea to the sea of the Philistines, and from the wilderness to the River Euphrates; for I will deliver the inhabitants of the land into your hand, and you will drive them out before you.