"I will harden the heart of Pharaoh..."

I have contended elsewhere that the title text need not imply any extraordinary action on God's part, and it is sufficient for the narrative that God allow Pharaoh's heart to harden itself.

At the same time, being an individual of some stubbornness and occasional truculence, I know so closely how it's quite possible that what hardened Pharaoh's heart was the knowledge of goodness (and, again, there is Malachi). Can you imagine a voice speaking truth in Pharaoh's heart: "You have let them start out, and that will be to the good; but are you still reluctant? See how futile your beast gods have proved! and how weak and sickly their service has made your children, your firstborn! Will you not turn to me and join your worship with my people's?" et.c. For: Pharaoh has a choice to make: to forsake the gods that proved false, or to try still to serve them. The choice was foretold, but that does not mean it was made for him or without him.