The written word acquired unparalleled significance with the arrival of Islam in the Arabian Peninsula. The Prophet Muhammad's trusted companions and followers collected the divine revelations from written and oral sources and compiled them into a manuscript known as the Qur'an, Islam's holiest book. Since the divine revelations were conveyed to the Prophet Muhammad in Arabic, Muslims regard the Qur'an in Arabic script as the physical manifestation of God's message. Copying text from the Qur'an is thus considered an act of devotion. The organic link of the Arabic language to Islam elevated it to the lingua franca, or common language, of the Islamic world.
The text of the Qur'an was codified in its present form under the Caliph 'Uthman ibn 'Affan (reigned 644–56). To preserve the authentic pronunciation of the Qur'an, a system of diacritical (or accent) marks indicating short vowels was developed.