"Pharaoh summoned Moses and Aaron and said, 'Pray to the Lord to take the frogs away from me and my people, and I will let your people go to offer sacrifices to the Lord.' Moses said to Pharaoh, 'I leave to you the honor of setting the time for me to pray for you and your officials, and your people that you and your houses may be rid of the frogs, except for those that remain in the Nile.' 'Tomorrow,' Pharaoh said. Moses replied, 'It will be as you say, so that you may know there is no one like the Lord our God. The frogs will leave you and your houses, your officials and your people; they will remain only in the Nile.'" NIV translation
Pharaoh appears to have given in to the will of God as he asks Moses and Aaron to pray to the Lord on his behalf. It appears that he has offered unconditional surrender but, as we shall see, that is not the case.