Is God Hardening Pharaoh's Heart?

The purpose of the plagues is that they will convince Pharaoh to let the people go. But then in chapter 421, God says, you know, yeah, I'm going to harden Pharaoh's heart so he doesn't let you go. And this brings together something that we looked at briefly in part two of the podcast. The way I put it with my students is that God is playing a cat and mouse game with Pharaoh. We've seen this more than once, and we've never seen anything like it before.