Deuteronomy 7:21-23

Thou shalt not be affrighted at them; for Jehovah thy God is in the midst of thee, a great God and a terrible.

And Jehovah thy God will cast out those nations before thee by little and little: thou mayest not consume them at once, lest the beasts of the field increase upon thee.

But Jehovah thy God will deliver them up before thee, and will discomfit them with a great discomfiture, until they be destroyed.