wikishia:Featured Article/2021/03
Biʿtha means selection of prophet by God for guidance of people. The Prophet Muhammad (s) in the age of forty in the Hira' cave in Mount Nur (close to Mecca) has been chosen as prophet and the first verses of Qur'an 96 has been revealed to him. The Bi'tha, according to Shiite point of view, was the beginning of Islam and occurred in Rajab 27, 13 lunar years before Hijra (June 25, 610).
Before the mission of the Prophet (s) began, most people of that region were idol-worshiper. Other divine religions had some followers in different places of that region. However, after the beginning of the mission of the Prophet (s), Islam expanded and idol-worshiping was wiped away from Hijaz.
The anniversary of the beginning of the mission of the Prophet (s) is among the celebrations of Shiite and is known as Eid al-Mab'ath.