Isaiah 51:9
Awake, awake, put on strength, O arm of the LORD; awake, as in the ancient days, in the generations of old. Art thou not it that hath cut Rahab, and wounded the dragon? Awake, awake, put on strength, O arm of the LORD; awake, as in the ancient days, in the generations of old. Art thou not it that hath cut Rahab, and wounded the dragon?
It is a cry for God's power to awaken and clothe itself with strength as it did in ancient days and former generations. The wounding of the sea monster and the cutting in pieces of the proud power recall His overthrow of Egypt and His ancient victories in delivering His people, opening the deep waters to make a path for the ransomed to cross over. Those mighty deeds of the past are given as ground for present confidence that He will save again, so His people who know righteousness and have His law in their hearts need not fear the reproach of dying men nor the fury of the oppressor beside the Maker who spread out the heavens and founded the earth. The call belongs with thanksgiving for His goodness and loving-kindness and with the promise that His righteousness and salvation endure from generation to generation, comforting Zion and bringing the redeemed home with singing and everlasting joy when sorrow and mourning flee away. In the last conflict it therefore charges the remnant to hold the banner of truth firmly, proclaim God's law with faith in Jesus, and rebuild the old waste places and the foundations of many generations.
Call and Ancient Deliverance
The verse is a call and plea for the arm of the Lord to awake and put on strength as in the ancient days and in the generations of old. It asks the Lord to show His strength now as He did in ancient times. The cutting of Rahab and the wounding of the dragon recall past displays of that strength, His victory and deliverance in ancient deliverances. They point to God's defeat of Egypt and deliverance of His people.
The lines following the verse recall how He dried the sea, the waters of the great deep. They recall the sea opened as a way for the ransomed to pass through. He made the depths a way for the ransomed and redeemed to pass over and cross.
The call stands among words to those who follow after righteousness and seek the Lord. It is spoken to His people who know righteousness and have His law in their heart, to His people in whose heart is His law.
Assurance of Present Salvation
The chapter to which the call belongs brings assurance and hope because the Lord bears His people's burdens. It is a plea for the Lord to act with the strength He showed in ancient times, recalling His defeat of Rahab and the dragon. That cutting of Rahab and wounding of the dragon recalls His past victory and deliverance, and the words that follow connect that deliverance with drying the sea so the redeemed could cross. God's former acts of power are thus presented as grounds for confidence that He can deliver His people again, despite reproach and oppression.
Therefore those addressed are not to fear the reproach of men. No mortal man who dies like grass nor the fury of the oppressor is to be feared beside the Lord the Maker who stretched out the heavens and laid the foundations of the earth. The appeal belongs with thanksgiving for God's goodness and loving-kindness, with confidence that His righteousness is forever and His salvation from generation to generation. It promises the comfort of Zion and the nearness of righteousness and salvation. It promises that the redeemed of the Lord shall return to Zion with singing and everlasting joy while sorrow and mourning flee away, His past deliverance in drying the sea so the ransomed could cross grounding that promise.
The verse belongs to Isaiah 51-53, which reveal the life-giving Saviour furnished to fallen, sinful man as the only hope of a life that measures with the life of God. That Saviour stood at the head of humanity to enable men and women to become sons and daughters of God. Clothing His divinity with humanity, He encircled the human race with His human arm while grasping the throne of the Infinite with His divine arm, placing man on vantage ground with God the Infinite Father.
Final Restoration and Trust
The cry for the arm of the Lord to awake and put on strength as in ancient days when Rahab was cut in pieces and the dragon wounded is addressed to those who know righteousness and have God's law in their heart, bidding them not to fear the reproach of men. In the final conflict, amid general departure from truth and righteousness, it charges the remnant to hold the banner of truth firmly and to proclaim the law of God joined with the faith of Jesus. It calls them to build the old waste places and to raise up the foundation of many generations.
The chapter belongs with rebuilding what has been ruined and restoring the paths and foundations laid by earlier generations. That restoring work stands in connection with honoring the Sabbath.
The same call gives assurance and hope in tedious, painful affliction, for the Lord strengthens by His grace for needed work and bears all burdens. Affliction is thus for the glory of the Lord and is to be endured without murmuring, trusting that Jesus looks upon the sufferer when waking in the night. Salvation comes by the Lord's own arm, for as God alone rescued Edson from hopelessness, gave him hope, and led him to rely wholly on Christ, so the one rescued is to look to God rather than trust human counselors.