Deuteronomy 7:16-20

And thou shalt consume all the people which the LORD thy God shall deliver thee; thine eye shall have no pity upon them: neither shalt thou serve their gods; for that will be a snare unto thee.

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

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

The 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.

Moreover the LORD thy God will send the hornet among them, until they that are left, and hide themselves from thee, be destroyed.