Charles Ellicott Commentary 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 Jehovah bindeth up the hurt of his people, and healeth the stroke of their wound." — Isaiah 30:26 (ASV)

The light of the moon shall be ... — The vision of the future expands, ascending from the new earth to the new heaven. With the passionate joy in light that recognizes in it, in proportion to its intensity, the symbol of Divine glory, Isaiah beholds a world where the sun and moon shall shine with a brightness that would now be intolerable, but which shall then be an element of delight.

In the day that the Lord bindeth up. — The day of blessing follows the day of judgment. Even that had, for God’s true servants, been the beginning of blessings, but this was only the earnest of a more glorious future. Isaiah reasons as St. Paul does: If one is the reconciling of the world, what shall the other be but life from the dead? (Romans 11:15). (Compare also Deuteronomy 32:39.)