Moses sings about God causing the sea to cover Pharaohs chariots and army as if God had thrown them into the sea. AT: "he has made the sea cover over Pharaoh's chariots and army" or "He has made Pharaoh's chariot riders and army drown in the sea" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Just as a stone does not float but sinks to the bottom of the sea, the enemy soldiers sank to the bottom of the sea. AT: "they went down into the deep water like a stone sinking to the bottom of the sea" (See: [[rc://en/ta/man/translate/figs-simile]])