Qur'anic Authenticity

الٓر ۚ تِلْكَ ءَايَـٰتُ ٱلْكِتَـٰبِ وَقُرْءَانٍ مُّبِينٍ

Alif, Lām, Rā. These are the verses of the Book and a clear Qur’ān [i.e., recitation].

وَإِنَّهُۥ لَفِى زُبُرِ ٱلْأَوَّلِينَ

And indeed, it is [mentioned] in the scriptures of former peoples.

وَمَا هُوَ بِقَوْلِ شَاعِرٍ ۚ قَلِيلًا مَّا تُؤْمِنُونَ

And it is not the word of a poet; little do you believe.

وَمَا هُوَ بِقَوْلِ شَيْطَـٰنٍ رَّجِيمٍ

And it [i.e., the Qur’ān] is not the word of a devil, expelled [from the heavens].