Exodus 15:4

Pharaoh's chariots and his host hath he cast into the sea: his chosen captains also are drowned in the Red sea.

Pharaoh's chariots and his host hath he cast into the sea. The Hebrew word rendered "cast" signifies what is hurled with great force, as an arrow shot from a bow, and it describes the fearful rapidity of the destruction which overwhelmed the Egyptians.

His chosen captains, х shaalishaayw (H7991)] - third men [Septuagint, Tristatas; see the note at Exodus 14:7.

In the Red Sea, х bª-Yam (H3220) Cuwp (H5488)] - in the sea of sedge or weeds. This was the name given by the Hebrews and the Egyptians to that bay or gulf of the Indian Ocean which was called "the Red Sea by the Greek geographers. 'On the waters of the "Red Sea"' says Dr Phipson, 'a species of algae, Trichodesmium Erythraeum, belonging to the group Oscillariae, is found sometimes in prodigious quantities. It is a microscopic plant, and of such a magnificent blood-red colour that there can be little doubt Herodotus gave the name of "Red Sea" to the Arabian Gulf from this circumstance. After a certain time these algae completely lose their red colour and become green, so that the phenomenon is intermittent.'