Usool At-tafseer by Shu‘bah ibn al-Hajjaaj, Sufyaan ibn ‘Uyaynah and it was translated by Dr. M. Abdul Haq Ansari

The revelation of the Qur’aan in seven different dialects made its recitation and memorization much easier for the various tribes. For example, the phrase, “ ‘alayhim” (on them), was read by some as “ ‘alayhumoo,” and the word “ siraat” (path, bridge), was read by some as “ siraat” and by others as “ ziraat,” and the word “mu’min” (believer) was also read as “moomin.” As a result, a greater number of the Prophet’s followers were able to memorize large portions of the Qur’aan while the Prophet (ﷺ) was still alive. Since the majority of the Arabs could neither read nor write and most of the Qur’aan was preserved during the Prophet’s lifetime by memorization, any factor which eased its memorization was of great importance. Hence, it could be said that the revelation of the Qur’aan in seven forms played a vital role in the actual preservation of the Qur’aan. It should also be noted that during the compilation of the Qur’aan after the Prophet’s death, the only means of verifying the correctness of what had been written of the Qur’aan during the Prophet’s lifetime was by comparing it with what had been memorized. Hence, the more people who were able to memorize it, the more accurately it could be compiled and verified. Consequently, the ease in memorization also played a key role in the accurate compilation of the Qur’aan.

In many places in the Qur’aan, Allaah challenged the Arabs of that time to produce a chapter similar to even its smallest chapter. The inability to imitate the Qur’aan’s style was a miracle which proved that the Qur’aan had to be from Allaah. This miracle became even more obvious when none of the seven major tribes could imitate it even in their own dialects, as no one could claim that it was difficult to imitate due to it not being in their own dialect