Exodus 23:28-30

And I will send hornets before you, which shall drive out the Hivite, the Canaanite, and the Hittite from before you. I will not drive them out from before you in one year, lest the land become desolate and the beasts of the field become too numerous for you. Little by little I will drive them out from before you, until you have increased, and you inherit the land.