10aMoses and Aaron performed all these wonders before Pharaoh; yet bthe Lord hardened Pharaoh's heart, and he did not let the sons of Israel go out of his land.
a
Exodus 4:21
Exodus 4
21
The Lord said to Moses, "When you go back to Egypt see that you perform before Pharaoh all athe wonders which I have put in your power; but bI will harden his heart so that he will not let the people go.