Isaiah 65:16

that he who blesseth himself in the earth, calling down some blessing upon his head, shall bless himself in the God of truth, literally, "in the God of Amen," in Him who fulfils all His promises to His children and executes His threats upon His enemies; and he that sweareth in the earth shall swear by the God of truth, because the former troubles are forgotten, with all the doubts which they tended to create in the hearts of the believers, and because they are hid from Mine eyes, so that they have disappeared entirely. This thought fitly introduces the next paragraph, where the new order of things is described in language which is both beautiful and majestic.