Moses lost the debate about going to Egypt. Now Yahweh assures (and terrifies) him that He will bless His people. Israel is the Lord’s firstborn whom He will deliver from Pharaoh, passing over when He sees the blood. After Zipporah circumcises Gershom, He sees the blood and passes over. Aaron speaks, Moses performs the signs for Israel, and they believe and worship, a sign of greater things to come. God will redeem His firstborn Son.