What did it mean for Israel when they went down into Egypt and left the promised land?
Going down to Egypt meant Israel left the land of promise and, nationally, entered a place pictured as outside God's control and a place of death, so it seemed God had lost His covenant people. Yet God promised to make them a great nation there.
Les teaches that with the invitation to come back to Egypt, Jacob was stammering, but God came to his rescue at Beersheba. God told Israel, 'Fear not to go down into Egypt, for I will there make of thee a great nation.' Les points out this is where the nation of Israel came from: the twelve sons, their wives, and children ended up in Egypt because Joseph had the food. Yet Les also emphasizes that when the brethren rejected all this, for all practical purposes Israel ended up in a place out of God's control, or a place of death nationally. They were out of the land of promise and down in Egypt, so it seemed God had lost His covenant people. This sets up Exodus as a book of redemption.