Exodus 23:27-30

I will send my fear before thee, and will destroy all the people to whom thou shalt come, and I will make all thine enemies turn their backs unto thee. And I will send hornets before thee, which shall drive out the Hivite, the Canaanite, and the Hittite, from before thee. I will not drive them out from before thee in one year; lest the land become desolate, and the beast of the field multiply against thee. By little and little I will drive them out from before thee, until thou be increased, and inherit the land.