Exodus 14:4-5

4Then I will harden Pharaoh’s heart, so that he will pursue them; and I will gain honor over Pharaoh and over all his army, that the Egyptians may know that I am the Lord.” And they did so.

5Now it was told the king of Egypt that the people had fled, and the heart of Pharaoh and his servants was turned against the people; and they said, “Why have we done this, that we have let Israel go from serving us?”