How did a difference occur in the words of some copies of the Qur’an between the Arab East and West, even though the Qur’an was written in the language of Quraysh and all other versions were burned during the reign of Caliph Uthman?

The Qur’an was revealed in seven ahruf (modes of recitation), and it is not established that it was revealed in ten. The differences between the masahef (copies of the Qur’an) today are a result of the differences in the masahef that were written during the time of Uthman, may Allah be pleased with him. In some of them, additions that were authentically transmitted from the Messenger of Allah, peace and blessings be upon him, and which the Companions and their successors received from him, were written. These additions were the cause of the differences in recitations. Examples of this include their difference in the inclusion or omission of the letter waw in Allah’s saying: "وَالَّذِينَ اتَّخَذُوا مَسْجِدًا ضِرَارًا" (And those who acquired a mosque for harm), and His saying: "فَلَا يَخَافُ" (and he does not fear) and "وَلَا يَخَافُ" (and he does not fear), and His saying: "وَيَقُولَ الَّذِينَ آمَنُوا" (and those who believed will say) and "يَقُولَ الَّذِينَ آمَنُوا" (those who believed will say). Uthman ordered that copies of the Qur’an be transcribed and distributed to the major cities. These masahef were stripped of dots and diacritics to encompass what was authentically transmitted and established in recitation from the Prophet, peace and blessings be upon him. The differences between the masahef are not only in vowel marks and dots but also in letters and words.