The Quran and other Divine Scriptures are not separate books. They are the different editions of a single Book of God which has been named al-kitab here. All editions of the Book revealed by God were one and the same as regards content. However, the bearers of the previous scriptures could not in the later periods preserve them in their original form. Therefore, God revealed His Book (muhaymin) i.e. the Quran, the authentic expression of His will, — a touchstone which reveals which sections of the other scriptures have retained their original form and which have been changed.