According to the Muslim belief and Islamic scholarly accounts, the revelation of the Qur'an began in 610 AD when the angel Gabriel (Arabic: جبريل, Jibrīl or جبرائيل, Jabrāʾīl) appeared to Muhammad in the cave Hira near Mecca, reciting to him the first verses of Surah Al-Alaq. Muslims believe that Muhammad continued to have revelations for the rest of life until his death in 632 AD.According to Islamic tradition, the Qur'an was first compiled into a book format by Zayd ibn Thabit and other scribes under the first caliph — Abu Bakr Siddiq. As the Islamic Empire began to grow, and differing recitations were heard in far-flung areas, the Quran was recompiled for uniformity in recitation (r. 644–56). under the direction of the third caliph — Uthman ibn Affan. For this reason, the Qur'an as it exists today is also known as the Uthmanic codex. According to Professor Francis Edward Peters (1991), what was done to the Quran in the process seems to have been extremely conservative and the content was formed in a mechanical fashion to avoid redactional bias.