Exodus 4:18-23 — It was time for Moses’ to leave his father-in-law in Midian and return to Egypt. As he was leaving the LORD gave Moses some very specific instructions and He also told Moses what He was going to do. Moses was to perform signs before Pharaoh and bring God’s message. The LORD was going to harden Pharaoh’s heart such that he would not obey. We know from the events that followed that it all came to pass just as God had said.
When we ponder this, we see God’s sovereignty at work and we also see man’s responsibility. Moses was the human instrument through which God brought to pass that which He had decreed. The LORD was going to redeem his “firstborn son” and that’s exactly what He did. This is the story of Exodus.