Isaiah 51 · a question people ask
Who is Rahab in 51:9, and what is the monster?
The verse doesn't explain either. It asks, "Isn’t it you who cut Rahab in pieces, who pierced the monster?" (51:9) (tap Rahab, cut), and the next verse goes on to the sea: "Isn’t it you who dried up the sea" (51:10). The Hebrew Bible has this Rahab, Strong's H7294, in three verses: this one, "I will record Rahab and Babylon among those who acknowledge me" (Psalm 87:4), and "You have broken Rahab in pieces, like one of the slain" (Psalm 89:10). The chapter on Psalm 87 studies the name, and the chapter on Isaiah 30 asks who Rahab is in "I have called her Rahab who sits still" (Isaiah 30:7). It isn't Rahab of Jericho (Joshua 2:1), whose name is spelled with a different Hebrew letter. Monster is tannin, the dragon of "he will kill the dragon that is in the sea" (Isaiah 27:1), and the chapter on Isaiah 27 studies it beside leviathan. These notes don't identify Rahab or the monster further than the verses do.
The verses
“Awake, awake, put on strength, arm of the LORD! Awake, as in the days of old, the generations of ancient times. Isn’t it you who cut Rahab in pieces, who pierced the monster? Isn’t it you who dried up the sea, the waters of the great deep; who made the depths of the sea a way for the redeemed to pass over?”
“I will record Rahab and Babylon among those who acknowledge me. Behold, Philistia, Tyre, and also Ethiopia: “This one was born there.””
“You have broken Rahab in pieces, like one of the slain. You have scattered your enemies with your mighty arm.”
“For Egypt helps in vain, and to no purpose; therefore I have called her Rahab who sits still.”