The call to prayer rings out from the Grand Mosque in Mecca.
It's the first day of Haj, the holy pilgrimage all physically able Muslims are required to make during their lives.
Millions of Muslims from around the world have descended on Mecca seeking forgiveness for their sins.
Up to three million pilgrims are expected in Saudi Arabia by the time Eid al-Adha is celebrated on Sunday.
(SOUNDBITE) (Arabic) AHMED AL MASRI, EGYPTIAN PILGRIM, SAYING:
"Every Muslim is waiting for this day to get rid of his sins, Allah descends to the lowest heaven and says: Is there someone who seeks forgiveness so I can forgive him? All Muslims await the day of Arafat so that God can forgive our sins."
(SOUNDBITE) (English) UNIDENTIFIED WOMAN, SAYING:
"I am very happy that I am going to Arafat mountain, I will pray for everybody."
Saudi Arabia regards itself as the guardian of Islam and takes responsibility for pilgrim security.
Several deadly incidents have marred past Haj seasons such as fires, hotel collapses, police clashes with protesters and stampedes.
Lily Grimes, Reuters
