The event of Ghadir Khumm refers to the appointment of Ali ibn Abi Talib by the Islamic prophet, Muhammad, as his successor according to the Shia beliefs. On February 632, last year of his life, Muhammad attended Hajj rituals known as farewell pilgrimage. On 18th Dhu al-Hijjah and on the way back to Medina, due to revelation of the verse of announcement, Muhammad gathered all Muslims and made a speech. The most significant sentence of his remark was: "Whomsoever to him I am master (Maula), Ali is also his/her master (Maula). O God, love those who love him, and be hostile to those who are hostile to him."