Canonization of Islamic scripture.Compilation and preservation

Following Muhammad's death in 632, a number of his companions who memorized the Quran were killed in the Battle of al-Yamama by Musaylima. The first caliph, Abu Bakr (r. 632–634), subsequently decided to collect the book in one volume so that it could be preserved. Zayd ibn Thabit (d. 655) was the person to collect the Quran since "he used to write the Divine Inspiration for Allah's Apostle". Thus, a group of scribes, most importantly Zayd, collected the verses and produced a hand-written manuscript of the complete book. The manuscript according to Zayd remained with Abu Bakr until he died. Zayd's reaction to the task and the difficulties in collecting the Quranic material from parchments, palm-leaf stalks, thin stones (collectively known as suhuf, any written work containing divine teachings) and from men who knew it by heart is recorded in earlier narratives. In 644, Muhammad's widow Hafsa bint Umar was entrusted with the manuscript until the third caliph, Uthman (r. 644–656), requested the standard copy from her. According to historian Michael Cook, early Muslim narratives about the collection and compilation of the Quran sometimes contradict themselves: "Most ... make Uthman little more than an editor, but there are some in which he appears very much a collector, appealing to people to bring him any bit of the Quran they happen to possess." Some accounts also "suggest that in fact the material" Abu Bakr worked with "had already been assembled", which since he was the first caliph, would mean they were collected when Muhammad was still alive.
In about 650, Uthman began noticing slight differences in pronunciation of the Quran as Islam expanded beyond the Arabian Peninsula into Persia, the Levant, and North Africa. In order to preserve the sanctity of the text, he ordered a committee headed by Zayd to use Abu Bakr's copy and prepare a standard text of the Quran. Thus, within 20 years of Muhammad's death in 632, the complete Quran was committed to written form as the Uthmanic codex. That text became the model from which copies were made and promulgated throughout the urban centers of the Muslim world, and other versions are believed to have been destroyed. The present form of the Quran text is accepted by Muslim scholars to be the original version compiled by Abu Bakr. This preservation of the Quran is considered one of the miracles of the Quran among the Islamic faithful.
Shias recite the Quran according to the qira'at of Hafs on authority of ‘Asim, which is the prevalent qira’at in the Islamic world and believe that the Quran was gathered and compiled by Muhammad during his lifetime. It is claimed that the Shia had more than 1,000 hadiths ascribed to the Shia Imams which indicate the distortion of the Quran and according to Etan Kohlberg, this belief about Quran was common among Shiites in the early centuries of Islam.