Exodus 11:9
The LORD told Moses, "Pharaoh won't listen to you. As a result, my wonders will increase throughout the land of Egypt."
Exodus 7:3-4
I'll harden Pharaoh's heart and I'll add more and more of my signs and wonders in the land of Egypt.
Exodus 3:19
I know that the king of Egypt won't allow you to go unless compelled to do so by force,
Exodus 10:1
Then the LORD told Moses, "Go to Pharaoh, for I've hardened his heart and the hearts of his officials in order to perform these signs of mine among them,
Romans 9:16-18
Therefore, God's choice does not depend on a person's will or effort, but on God himself, who shows mercy.