This letter actually revokes the law that had been issued previously. Darius calls on the nations of his kingdom to fear the Lord, the God served by Daniel, with reverence. He is the living God! The Lord is here recognized as the Eternal and Almighty by a world ruler who himself was worshipped as a god.
26 I make a decree, that in all my royal dominion people are to tremble and fear before the God of Daniel, for he is the living God, enduring forever; his kingdom shall never be destroyed, and his dominion shall be to the end.