Exodus 14:4-5

4I will harden Pharaoh’s heart, so he will follow after them. Then I will be glorified over Pharaoh along with all his army, and the Egyptians will know that I am Adonai.” So they did so.

5When the king of Egypt was told that the people had fled, Pharaoh and his servants had a change of heart toward the people, and they said, “What is this we have done, that we let Israel go from serving us?”