If you are in doubt as to what We have sent down to Our servant, then bring a chapter like this, and call upon your witnesses other than God if you are truthful.
Translation endnotes
[2:23-24] These verses primarily refer to the mathematical system of the Quran. The most popular position among Muslim scholars is that the miracle of the Quran is its literary excellence. This is, however, an imaginary or false claim, since there is no objective or universal criteria for comparing literary texts and thereby preferring one over the other. The miraculous nature of the Quran or the Quran's claim of divine authorship and its universal appeal cannot be relegated merely to the literary taste of those who know Arabic, which may change subjectively. It is impossible to argue that the Quran is divine by comparing its literary aspects to those of Al-Mutanabbi, Taha Hussain or any other Arabic literary work. Bukhari and Ibn Hanbal, the two so-called authentic hadith collections of Sunnism, tacitly confess the impossibility of distinguishing the Quranic statements from man-made literary works since they narrate a text, which is still uttered by millions of Sunni mushriks in “bonus” prayers called nawafil. According to their report, Ibn Masud, one of the most prominent comrades of prophet Muhammed, and allegedly one of the most prolific sources of hadith, had included that prayer to his Quran as an independent chapter while expunging the last two chapters. The claim of medieval Sunni and Shiite sources regarding the requirement for two witnesses for each verse to authenticate their divine nature, regardless of the truth-value of the claim, is another acknowledgment of their inability to distinguish a Quranic revelation from fabricated statements via the socalled literary excellence criterion. See 4:82; 10:20; 74:30, and the Appendix titled On it Nineteen.