Verse 3
The great dragon - התנים hattannim should here be translated crocodile, as that is a real animal, and numerous in the Nile; whereas the dragon is wholly fabulous. The original signifies any large animal.
The midst of his rivers - This refers to the several branches of the Nile, by which this river empties itself into the Mediterranean. The ancients termed them septem ostia Nili, "the seven mouths of the Nile." The crocodile was the emblem of Egypt.