According to Muslim belief, at the age of 40, Muhammad is visited by the angel Gabriel while on retreat in a cave named Hira on Mount Jabal al-Nour, near Mecca. The angel recites to him the first revelations of the Quran and informs him that he is God's prophet. Later, Muhammad is told to call his people to the worship of the one God, but they react with hostility and begin to persecute him and his followers.