He is The One Who drove the ones who disbelieved among the Population of the Book (Or: The Family of the Book, i.e., the life of this world) out of their homes at the first mustering. In no way did you surmise that they would go out, and they surmised that their fortresses would hold them back from Allah. Then Allah came upon them from where they did not (expectedly) reckon, and He hurled horror in their hearts (as) they ruined their houses with their (own) hands and the hands of the believers. So ponder (on that), you who are endowed with beholdings! (i.e., eyesight (s)