Exodus 23:27-30

27“I will send my terror ahead of you and throw into confusion every nation you encounter. I will make all your enemies turn their backs and run. 28I will send the hornet ahead of you to drive the Hivites, Canaanites and Hittites out of your way. 29But I will not drive them out in a single year, because the land would become desolate and the wild animals too numerous for you. 30Little by little I will drive them out before you, until you have increased enough to take possession of the land.