The Quran has explicitly recorded about what has become of the body of Fir'aun.

"This day We save therein your body so that you become a sign for those who come after you. But verily, many among mankind are heedless of our signs......" (10:92)

In this verse, the God's intention of bringing the body of Pharaoh out of water rather than leaving it decaying or being eaten by the sea animals is to give a lesson to future generations.

What is amazing that when the Quran was transmitted to man by
the Prophet, the bodies of all the Pharaohs were in their tombs in the Necropolis of Thebes, on the opposite side of the Nile from Luxor. At the time however, absolutely nothing was known of this fact, and it was not until the end of the nineteenth century that they were discovered there.

As the Quran states, the body of the Pharoah (Fir'aun) of the Exodus was in fact rescued: visitors may see him in the Royal Mummies Room of the Egyptian Museum, Cairo. How did the Prophet, who lived in Arabian desert came to know that the body of Fir'aun would be rescued for future generations to learn a lesson?