The First Possibility

The First Possibility: Pharaoh's faith happened right after seeing the parting of the sea.

This possibility is incorrect due to the Almighty's saying: {We took the Children of Israel across the sea, and Pharaoh and his soldiers pursued them in tyranny and enmity, until when the drowning caught up to him, he said, "I believe . . .”}. Pharaoh pursued the children of Israel, that is, seeing the parting was not enough for him. Instead, he commanded his soldiers to descend to the seabed and pursue the Children of Israel {and Pharaoh and his soldiers pursued them in tyranny}.