It is a promise binding on Us. (Q21:104)

In fact, it is a Glorious Quran, in a Preserved Tablet.(Q85:22-23)

This is an oath, if you only knew, that is great. It is an honorable Quran. In a protected record. None can grasp it (the Quran) except those PURE (unmixed between nature & unnature). (Q56:76-80)

In fact, it (the Quran) is a clear revelation in the chests of those who have been given knowledge. (Q29:49)

What does it mean to believe in the Quran?

But as for those who [1] have clear evidence from their LordLaw (of Nature, Sunnatullah) , [2] followed up by a (natural person) witness from Him (revelation) — and [3] before it the ordain/jihad of Musa came as a model (for natural society) and a mercy (for Natural Law) — such people have iman in it (the Quran). Any faction which rejects it is promised the Fire. Be in no doubt about it. It is the Truth from your Lord. But most people have no iman. (Q11:17)