Isaiah 30:26
Moreover the light of the moon shall be as the light of the sun, and the light of the sun shall be sevenfold, as the light of seven days, in the day that the LORD bindeth up the breach of his people, and healeth the stroke of their wound.
The verse looks forward to the future restoration of God's people in the day that the Lord binds up their breach and heals the stroke of their wound, after the conflict is over and after the final battle has been fought and the victory is won. It belongs to the time when the church is no longer militant, but triumphant. In that day the world will be filled with and bathed in the light of heaven.
The light of the moon shall then be as bright as the present light of the sun, and the light of the sun shall be seven times, or sevenfold, brighter and greater than now. This greatly increased brightness of moon and sun marks the healing and renewal of the world when God's victory is complete. It means God's will shall then be done on earth as it is done in heaven. Then the kingdom of peace and joy and everlasting righteousness shall be established, and the nations shall own no other law than the law of heaven.
Now the church is militant in midnight darkness, but then the church triumphant shall stand beside the gates of the city and receive her King with joy. All the redeemed shall be a happy, united family clothed in the robe of Christ's righteousness. All nature in surpassing loveliness shall offer constant praise and adoration to God, and the years shall move on in gladness. Over that joyful, sinless life of the saved the morning stars shall sing together and the sons of God shall shout for joy, while God and Christ unite in proclaiming that there shall be no more sin and no more death.