There are four aspects that wrap up the inimitability of the Qur’an:
1- The perfection of its authorship and the cohesion of its structure along with its ultimate eloquence and conciseness.
2- The elegance of its style; it is composed of a significantly different style than that of the leaders of eloquence among Arabs in both poetry and prose. Its style has blown up the minds of those leaders who couldn’t bring forth anything similar to it despite the well-conditioned circumstances to do so.
3- The rich reports it has about the previous nations and their respective legislations whose knowledge was only known by a very few people among the people of the Book.
4- Its rich content that foretells future events; some of them occurred during the Prophetic period and others after it.
Source: Fath al-Bary fee sharh Sahih al-Bukhari: (8/623)
Translated by: Abdullah Ibrahim Omran al-Misri.