Answered by Ustadh Tabraze Azam
Question:  Was the whole Quran compiled during the Prophet’s lifetime or after he (Allah bless him and give him peace) passed away?  Why were some copies of the Quran burnt?
Answer: Assalamu alaikum wa rahmatullahi wa barakatuh,
I pray that you are in the best of health and faith, insha’Allah.
Sh `Ali Hani, a master of Qur’anic Tafsir and related sciences, said that:
 The whole Qur’an was compiled during the life of the Messenger of Allah (Allah bless him and give him peace).
 Copies of the Qur’an which some had in their possession were burnt when our master `Uthman (Allah be pleased with him) ordered the writing of ‘standardized’ copies of the Qur’an.
Many people during the time of `Uthman had their own explanatory notes in their personal copies of the Qur’an. Others had written down portions of the Qur’an themselves. In order to prevent any future issues of explanatory notes being considered as part of the Qur’an or arguments due to a mistake on the part of the writer – claiming that he has something of the Qur’an which others do not have – these old copies were burnt.
Next, the Caliph `Uthman ordered a group of the companions to write down the Qur’an in an official, standardized copy and these new copies along with recitors were sent to peoples of different lands. This was done out of their love of the Qur’an and avidness that revelation be preserved, unaltered.
And Allah knows best.
Checked & Approved by Faraz Rabbani