The Response of God to Pharaoh

The fact that someone could go into a house and be spared from one of the plagues has happened before in the plague of the hail. So what that leads you to believe is there's a lot of Egyptians who are taking Moses seriously at this point. A lot of Egyptians went with Israel out of Egypt because we're told in the story when they leave that a whole bunch of different kinds of people went, not just Israelites left.