Thou art like a young lion - and thou art as a whale in the seas - Thou mayest be likened to two of the fiercest animals in the creation; to a lion, the fiercest on the land; to a crocodile, תנים tannim, (see Ezekiel 29:3;), the fiercest in the waters. It may, however, point out the hippopotamus, as there seems to be a reference to his mode of feeding. He walks deliberately into the water over head, and pursues his way in the same manner; still keeping on his feet, and feeding on the plants, etc., that grow at the bottom. Thus he fouls the water with his feet.
Thou art like - Rather, Thou wouldest be like to (others, “wast likened unto”) a young lion.
And thou art - In contrast to what thou wouldest be.
A whale - Rather, crocodile (marginal reference note). Pharaoh should have been like the king of beasts, but he is a mere sea-monster. There is strong irony here, because the Egyptian king was proud of the comparison between himself and the mighty crocodile.
Seas - The word is often used of the waters of a great river, like the Nile.
Thou camest forth with thy rivers - Rather, thou didst burst forth in “thy rivers” as the crocodile does from the water into which he has plunged.