Exodus 4:21
And the Lord said to Moses, When you go back to Egypt, see that you do before Pharaoh all the wonders which I have given you power to do: but I will make his heart hard and he will not let the people go.And the Lord said to Moses, When you go back to Egypt, see that you do before Pharaoh all the wonders which I have given you power to do: but I will make his heart hard and he will not let the people go.