Revelation 12:8 - Ellicott's Commentary On The Whole Bible

And prevailed not... — Better, And their power failed them, and not even was place for them found any more in the heaven. The result of the war was the dragon’s defeat. The whole power of the evil hosts failed them. There is an inherent weakness in evil: a spot which may be touched whereupon all its vaunted strength withers. So complete was the overthrow, that even their place knew them no more. “I went by, and, lo! he was gone; I sought him, but he could nowhere be found.”