"Rahab" would seem to be a symbolical expression for Egypt. "Rahab" is literally "pride," or "the proud one." The event alluded to, both here and in Psalm 89:10, is the destruction of Pharaoh's host in the Red Sea. "The dragon" is another symbol of the Egyptian power (comp. Ezekiel 29:3, "Pharaoh, King of Egypt, the great dragon that lieth in the midst of his rivers"). Originally designating God's great enemy, Satan (Genesis 3:14; Revelation 12:7-9; Revelation 20:2), it is a term which comes to be applied to the adversaries of the Almighty generally."