Hazrat Zayd bin Thabit (رضی اللہ تعالیٰ عنہ) was one of the Ahle-Suffa, spending all of his time in the company of the Messenger of Allah. Because of his sharp memory and extraordinary intelligence, the Messenger of Allah chose him for special tasks such as writing down the Holy Quran. Thus he is counted amongst the senior most of scribes of the revelation. He also had most of the Quran with him in written form.
He memorized the Quran with such grace that even the Holy Prophet ﷺ used to ask him to recite it. He also served as the Messenger of Allah's secretary until he passed away. The first caliph Abu Bakr (رضی اللہ تعالیٰ عنہ) & retained Zayd's position as a scribe and included him in his Shoora (Advisory Council). He participated in the battles against the false prophets and was injured in the battle of Yamama against Musailima the liar.
Zayd bin Thabit (رضی اللہ تعالیٰ عنہ) was appointed the head of the team that
began the compilation of the Quran during Abu Bakr's time. He approached each
and every person possessing any part of the Quran and after carefully
confirming authenticity made it part of the original copy. He made a standard.
The contributing person must not only know the verses by heart but also have them
with him in writing. Then his contribution must be backed up by at least two
companions.
Finally, after Abu Bakr's death, the copy went to Umar and
after his death in the custody of Hafsa bint Umar (Holy Prophet's wife), and so
became known as the 'Mushaf-e-Hafsa'. During the caliphate of Usman (رضی
اللہ تعالیٰ عنہ), it
was decided that a standard manuscript of the Quran be prepared. He was
appointed as part of the team to prepare seven such copies based on the
'Mushaf-e-Hafsa'.