It may seem a minor point in the story, but “hardening” is a big issue in the New Testament.
We must be very careful in this study if we wish to understand what the Word of God says on Pharaoh’s hardening. The first thing to notice is that God knows the whole story before it commences. Thus, the first two times we hear of the hardening of Pharaoh’s heart (Ex 4:21; 7:3), they are prophecies; God wants Moses to know that this will be a lengthy battle between the Lord and Pharaoh. When the process actually starts, it is Pharaoh who begins it (8:15; 8:32). Second, notice the reason in God’s heart for doing this: “Now if I had stretched out My hand and struck you and your people with pestilence, then you would have been cut off from the earth. But indeed for this purpose I have raised you up, that I may show My power in you, and that My name may be declared in all the earth” (9:15-16). In other words, God could easily have destroyed the Egyptians and their king, but that was not His objective. He wanted to reveal Himself—to both Jews and Gentiles—and His vast superiority in ten distinct ways over all man-imagined gods. If Pharaoh had let Israel go immediately, this would not have been possible. And even after God steps in to control the rate at which Pharaoh’s heart hardens (9:12), it is not altogether hard, for Pharaoh then hardened it further (v 34). We will see how God gave Pharaoh evidence, which he mocked by calling his magicians to imitate it. Rather than destroy him, God said, in effect, If you don’t like the evidence where Moses and Aaron said this was the true God speaking, I’ll give you incontrovertible evidence so your own magicians will say it is My “finger” doing it. Still Pharaoh refused. Did the process work? We’ll see that it did, wonderfully. But more of that in our next lesson.