Exodus 23:28-30
23:28 I will send hornets before you that will drive out the Hivite, the Canaanite, and the Hittite before you.
23:29 I will not drive them out before you in one year, lest the land become desolate and the wild animals multiply against you.
23:30 Little by little I will drive them out before you, until you become fruitful and inherit the land.