(salam) Is 'the book' a record that is with Allah (SWT) i.e the ink has dried..everything is written down already. Is the verse saying there is no doubt in that writing? Not the Quran? (because Allah (SWT) describes to us the wrongdoers are plunged deeper in to error, and also from following allegory) that means the quran does cause doubt to hypocrites and disbelievers. Will look for the verses exactly. (bismillah) (1) He it is Who has sent down to thee the Book: In it are verses basic or fundamental (of established meaning); they are the foundation of the Book: others are allegorical. But those in whose hearts is perversity follow the part thereof that is allegorical, seeking discord, and searching for its hidden meanings, but no one knows its hidden meanings except Allah. And those who are firmly grounded in knowledge say: "We believe in the Book; the whole of it is from our Lord:" and none will grasp the Message except men of understanding. ( سورة آل عمران , Aal-e-Imran, Chapter #3, Verse #7) (12) Those who behave arrogantly on the earth in defiance of right - them will I turn away from My signs: Even if they see all the signs, they will not believe in them; and if they see the way of right conduct, they will not adopt it as the way; but if they see the way of error, that is the way they will adopt. For they have rejected our signs, and failed to take warning from them. ( سورة الأعراف , Al-Araf, Chapter #7, Verse #146)