Exodus 14:4-8

And I will harden Pharaoh’s heart, and he will chase after them; and I will be honored through Pharaoh and all his army, and the Egyptians will know that I am the Lord.” And they did so.

When 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 that we have done, that we have let Israel go from serving us?”

So he had horses harnessed to his chariot and took his people with him;

and he took six hundred select chariots, and all the other chariots of Egypt with officers over all of them.

So the Lord hardened the heart of Pharaoh, king of Egypt, and he chased after the sons of Israel as the sons of Israel were going out boldly.