Answer:
The holy book of Islam is called, The Quran. The Quran (sometimes spelled Qur'an or Koran) is considered the most important holy book among Muslims
Step-by-step explanation:
Muhammad's popularity was seen as threatening by the people in power in Mecca, and Muhammad took his followers on a journey from Mecca to Medina in 622. This journey is called the Hijrah (migration) and the event was seen as so important for Islam that 622 is the year in which the Islamic calendar begins.