Zayd ibn Thābit al-Ansāri, one of the scribes of the Qur'an, reported: Abu Bakr As-Siddīq sent for me when the people (of the battle) of Yamāmah were killed. I found ‘Umar ibn al-Khattāb sitting with him

Zayd ibn Thābit al-Ansāri (may Allah be pleased with him) reported that Abu Bakr As-Siddīq summoned him during his caliphate, after the Companions of the Prophet had fought against Musaylimah the Liar in the battle of Yamāmah in 11 AH. The battle was sparked due to Musaylimah's claim to be a prophet and also due to the apostasy of many of the Arabs. Many of the Prophet's Companions were killed in those battles. Zayd went to Abu Bakr and found ‘Umar sitting with him. Abu Bakr told Zayd that ‘Umar had come to him and told him that many of the Companions had been killed in their battles with Musaylimah and he feared that more of the Qur'an memorizers would be killed in subsequent battles with the disbelievers, and consequently parts of the Qur'an could be lost. So ‘Umar had proposed that the Qur'an should be collected. Abu Bakr wondered how he could do something that the Messenger of Allah had not done. ‘Umar replied that collecting the Qur'an would be better than leaving it scattered around. Abu Bakr said that ‘Umar had talked to him about collecting the Qur'an until he had felt comfortable with the idea and decided to collect it. Zayd ibn Thābit commented that ‘Umar was sitting there, silently. Then Abu Bakr said to Zayd that he was an intelligent young man whom they could not accuse of lying or forgetfulness. As Zayd had written the revelation for the Messenger of Allah, they suggested that he should track down the Qur'an and collect it. The whole Qur'an had been written down during the Prophet's life, but it had not been collected in one place nor were the Sūrahs arranged in their current order. Zayd commented that moving a mountain would have been easier for him than collecting the Qur'an. He wondered how Abu Bakr and ‘Umar could do something that the Prophet had not done. Abu Bakr said that this would be good, and he continued to talk to Zayd about the benefits of collecting the Qur'an until he felt comfortable with the proposal and decided to collect the Qur'an for the public interest. Zayd collected the Qur'an written on parchments, shoulder blades, and palm stalks, and also from the hearts of men who had fully memorized it, such as Ubai ibn Ka‘b and Mu‘ādh ibn Jabal. In this way, the text that was written on parchment and shoulder blades would be further evidence to what had been memorized by the Companions. He only found the last two verses of Sūrat At-Tawbah written down by Khuzaymah ibn Thābit al-Ansāri. These are the verses that state: {There has certainly come to you a Messenger from among yourselves. Grievous to him is what you suffer, [he is] concerned over you...} until the end of the two verses [Sūrat At-Tawbah: 128-129]. The sheets on which the Qur'an were collected remained with Abu Bakr until he died, then with ‘Umar until he died, and then with Hafsah, ‘Umar’s daughter (may Allah be pleased with them all). The Shias objected to Abu Bakr's collection of the Qur'an, because he had done something that the Messenger of Allah (may Allah's peace and blessings be upon him) had not done. Abu Bakr did not do anything objectionable, as he embarked on this project for the sake of Allah, His Messenger, and His Book. The Prophet (may Allah's peace and blessings be upon him) had allowed this as in the Hadīth reported by Abu Sa‘īd: ''Do not write anything from me other than the Qur'an.'' [Muslim]. So Abu Bakr did nothing other than collecting the Qur'an that was already written. Thus, the Shias' objection to Abu Bakr's collection is baseless.