And what goes before also establishes this interpretation. For he doth not merely say, “Behold, the Virgin shall be with child,” but having first said, “Behold, the Lord Himself shall give you a sign,” then he subjoins, “Behold, the Virgin shall be with child.” Whereas, if she that was to give birth was not a virgin, but this happened in the way of marriage, what sort of sign would the event be? For that which is a sign must of course be beyond the course of common events, it must be strange and extraordinary; else how could it be a sign?