Exodus 14:4-5

4And I will harden Pharaoh’s heart, and he will pursue them. But I will gain glory for myself through Pharaoh and all his army, and the Egyptians will know that I am the Lord.” So the Israelites did this.

5When the king of Egypt was told that the people had fled, Pharaoh and his officials changed their minds about them and said, “What have we done? We have let the Israelites go and have lost their services!”