TSK · Exodus 9:7

Yet Pharaoh’s heart became hard, and he did not listen to them, just as the LORD had predicted.

But Pharaoh hardened his heart this time also and did not release the people.

He is wise in heart and mighty in strength– who has resisted him and remained safe?

I did this because I know how stubborn you are. Your neck muscles are like iron and your forehead like bronze.

So then, God has mercy on whom he chooses to have mercy, and he hardens whom he chooses to harden.