The process started when Umar urged Abu Bakhr to collect the quran and hence Abu Bakhr appointed Thabit to compile the quran. See below.
Now let us reason.If 2 caliphs knew the quran by heart, they could have easily formed 2 witnesses amongst themselves and wrote the entire quran themselves but instead Abu Bakhr tells Umar that if 2 witnesses bring a verse to him, he should put it in quran. Isn’t this an admission from Abu Bakhr and Umar that they were not knowledgeable enough?? Why would they need people to come with 2 witnesses and tell them a particular verse if they already knew the entire quran? If this is not enough proof then we can see an admission from Umar himself ( Click the spoiler below)that he or anyone did not know the entire quran and that there were people who were better than him in knowledge..
Secondly, Was Abu Bakhr attesting the work done by Umar in the real sense using his knowledge??
Abu Bakhr simply delegated the task of collecting the quran and was relying completely on Umar and Thabit. No where do we see Abu Bakhr actually attesting to the each and every verse of quran by giving his inputs using his knowledge so the real compilers of the first draft of quran were Umar and Thabit along with some other men who brought 2 witnesses and ABU BAKHR was not involved in the real sense.
Thirdly, did Uthman and Ali agree with this copy of Umar and company?
Uthman and Ali were not involved in the first draft of compilation so the first draft was not prepared by consent of 4 caliphs at all. Infact 3 of the caliphs were inactive. Uthman did not agree with the first draft at all when he prepared the final draft in 653 AD because he asked some quraish men and Thabit to make changes to the draft prepared by Umar and company. This is supported by the fact that Marwan burned the original copy with Hafsa (the daughter of caliph Umar) after her death in 665 AD because it was not in agreement with Uthman’s copy. Hafsa did not follow the Uthmanic quran. This shows that Uthmanic copy did not agree with Umar’s copy.
TO be CONTINUED....