Deuteronomy 7:17-19

17If thou shalt say in thine heart, These nations are more than I; how can I dispossess them?

18Thou shalt not be afraid of them: but shalt well remember what the Lord thy God did unto Pharaoh, and unto all Egypt;

19The great temptations which thine eyes saw, and the signs, and the wonders, and the mighty hand, and the stretched out arm, whereby the Lord thy God brought thee out: so shall the Lord thy God do unto all the people of whom thou art afraid.