The Hyperlinked Bible
Intertextuality Pair
Allusion
Later text
Awake, awake, put on strength, O arm of the LORD. Wake up as in days past, as in generations of old. Was it not You who cut Rahab to pieces, who pierced through the dragon? Was it not You who dried up the sea, the waters of the great deep, who made a road in the depths of the sea for the redeemed to cross over? So the redeemed of the LORD will return and enter Zion with singing, crowned with everlasting joy. Gladness and joy will overtake them, and sorrow and sighing will flee.
Earlier text
Isaiah 27:1BSB
In that day the LORD will take His sharp, great, and mighty sword, and bring judgment on Leviathan the fleeing serpent—Leviathan the coiling serpent—and He will slay the dragon of the sea.
The two texts share the rare noun תַּנִּין (tannin, "the dragon"). Isaiah 51:9 sets it beside רַהַב (Rahab) and חלל (chalal, "pierced through"): "Was it not You who cut Rahab to pieces, who pierced through the dragon?" Isaiah 27:1 sets the same noun beside לִוְיָתָן (Leviathan) and נָחָשׁ (nachash, the Genesis 3 word for serpent), with הרג (harag, "slay"): "He will slay the dragon of the sea." Same monster, same slayer — and opposite time-signatures.
That reversal is the substance of the connection. Isaiah 51:9 pleads with the arm of the LORD to "wake up as in days past (יְמֵי קֶדֶם), as in generations of old": the dragon-slaying lies behind. Isaiah 27:1 announces "in that day (בַּיּוֹם הַהוּא) the LORD will take His sharp, great, and mighty sword": the dragon-slaying lies ahead. And Isaiah 51:10 identifies the past victory without ambiguity — "Was it not You who dried up the sea... who made a road in the depths of the sea for the redeemed to cross over?" Rahab is Isaiah's name for Egypt (Isaiah 30:7), so the prophet has fused three things into a single divine act: the subduing of primeval chaos, the historical drowning of Egypt at the Red Sea, and the eschatological slaying of Leviathan. One enemy, one sword, three moments. Both methods are assigned for that reason — a single theme (the Divine Warrior against the chaos-monster) traced across the whole storyline from creation through the exodus to the last day.
The prayer of Isaiah 51:9 has an answer two chapters later, and it is not the answer the pray-er expects. "Awake, awake, put on strength, O arm (זְרוֹעַ, zeroa) of the LORD" is met by Isaiah 53:1: "to whom has the arm (זְרוֹעַ) of the LORD been revealed?" — and what follows is not a sword but a man despised and pierced. The arm that cuts Rahab to pieces is the arm that is itself pierced through. Revelation completes the identification: "the great dragon... that ancient serpent called the devil and Satan" (Revelation 12:9), thrown down by the blood of the Lamb (12:11) and finally consigned in Revelation 20:10.
Isaiah does not end the passage on the victory but on what the victory is for: "the redeemed of the LORD will return and enter Zion with singing, crowned with everlasting joy. Gladness and joy will overtake them, and sorrow and sighing will flee" (51:11). The dragon is slain so that joy can do the chasing.