Panel 7: The seventh panel is completely dedicated to "The passage through the Red Sea." Read from right to left, in the scene are synthesized three important moments in the Exodus. Presented as a bird's eye view, the scene opens on the right with the view of a city from which the Pharoah and his army rush out. Various squadrons of the army are shown--infantry, cavalry, and chariots--whereas the Biblical text speaks only of chariots sent out to pursue the Jews. On the left is shown the moment in which "Moses receives from the Lord the order to close, with a gesture of his hand, the waters of the Red Sea, after the Jews have crossed it, walking on foot over the bottom" (Exodus 14:26-31). The central zone thus becomes an illustration of the "Waters which, returning, submerge the Egyptian army" (Exodus 14:28). In the highest part of the scene, in the middle of the ruin of his troops, we see the detached figure of the Pharoah, who appears like a tragic figure, with his bust emerging from the waters, his gaze turned toward the sky, and his left arm wielding his shield in a fruitless effort to protect himself against divine wrath.
(From: Francesco Gandolfo, "La basilica sistina: i mosaici della navata e dell'arco trionfale," in Chiese Monumentali d'Italia. Santa Maria Maggiore a Roma, edited by Carlo Pietrangeli [Florence 1988] p. 96 [translated by Bernard Frischer]).