It usually refers to the sending of Muhammad to the people of the world, when the angel Jibril brought to him the first verses (ayat) of the Qur'an in the Cave of Hira on Jabal al-Nur near Mecca in 610 AD.
This event typically signifies the dispatch of Muhammad to the world's population, when the angel Jibril brought to him the first verses (ayat) of the Qur'an in the Cave of Hira on Jabal al-Nur near Mecca in 610 AD.