John Gill Commentary Deuteronomy 7:18

"thou shalt not be afraid of them: thou shalt well remember what Jehovah thy God did unto Pharaoh, and unto all Egypt;" — Deuteronomy 7:18 (ASV)

You shall not be afraid of them
Neither on account of their number, nor their strength:

but shall well remember what the Lord your God did to Pharaoh, and
to all Egypt ;
a people more numerous and potent than the Canaanites, among whom the Lord wrought such wonderful things by his power, which obliged them to let Israel go; and his power was now the same, he could do as great things to the Canaanites as he had done to the Egyptians; and as he had delivered them out of the hands of the Egyptians, he could as easily deliver the Canaanites into their hands, and put them into the possession of their country.