Whenever something is to be done needing great power, Michael is sent forth so that from his action and from his name we can understand that no one can do what God can do. Hence that old enemy who through pride desired to be like God, saying, "I will scale the heavens, I will set up my throne, I will be like the Most High," is shown at the end of the world left to his own strength, and about to undergo the final punishment, as destined to fight with Michael the Archangel. Similarly, Gabriel was sent to Mary; he who is called "strength of God" came to announce Him who deigned to appear in humility to conquer the powers of the air. And Raphael is interpreted, as we said, "Medicine of God," for when he touched the eyes of Tobias to do the work of healing, he dispelled the night of his blindness