Why did God tell Jacob not to be afraid to go down to Egypt?
God told Jacob not to fear going down to Egypt because He promised to make Jacob a great nation there, fulfilling the Abrahamic covenant. This assured Jacob that Egypt would be a place of growth and blessing, not harm, and after 215 years Israel came out as a vast company of millions.
Les explains that this instruction marked a change. God had told Abraham and Isaac not to go into Egypt, and when they tried it, they got into trouble until they returned to Canaan. But now God tells Jacob, “Don’t be afraid to go down into Egypt, for there in Egypt I will make of thee a great nation.” That is exactly what happened: after some 215 years of the children of Israel in Egypt, Moses led them out as a company of anywhere from 5–7 million people, making them the biggest nation in the then-known world by those standards. The Abrahamic covenant was repeated to Isaac and then again to Jacob.