this quran could not have been fabricated by anyone besides allah rather it is a confirmation of what was before it and an elaboration of the book there is no doubt in it from the lord of all the worlds.
وما كان هذا القرآن أن يفترى من دون الله ولكن تصديق الذي بين يديه وتفصيل الكتاب لا ريب فيه من رب العالمين