<P> Twelvers believe that since a prophet is appointed by God, only God can appoint his successor . Some cite Quranic verses such as 38: 26 and 2: 124 in which Allah assigned his successor on earth . Shia believe that Moses did not ask his people to conduct a shura and assign his successor; Allah selected Aron to succeed Moses for his 40 - night absence . Shia scholars refer to hadiths such as the Hadith of the pond of Khumm, Hadith of Position and Hadith of the Twelve Successors to prove that God, through Muhammad, chose Ali as successor . When the chief of Banu Amir asked Muhammad for a share of leadership in return for defeating Muhammad's enemy, Muhammad replied: "That is for God to decide; He will entrust leadership to whomever He will"; community leadership was not decided by the people . </P> <P> Ali, Muhammad's cousin and a leader in battle, was often entrusted with command and was left in charge of the community in Medina when Muhammad led the Battle of Tabouk . Ali was also the husband of Muhammad's daughter, Fatimah, and the father of his grandchildren Hasan and Husayn . Ali's father was Abu Talib ibn Abd al - Muttalib, Muhammad's uncle, foster father and protector . As a member of Abu Talib's family, Muhammad was like an older brother and guardian to Ali (who, as a youth, was among the first to accept Islam). A charismatic defender of the faith, Ali was assumed by some to claim a leadership position after Muhammad's death . In the end, however, Abu Bakr assumed control of the Muslim community . </P> <P> Shia refer to three verses from sura Al - Ma'ida: 5: 55, 5: 3 and 5: 67 . They believe that the verses refer to Ali, and the last two were revealed at Ghadir Khumm . </P> <P> Shia believe that a number of ahadith indicate that Muhammad left specific instructions about his successor . Some of these ahadith have names, such as the pond of Khumm, Safinah, Thaqalayn, Haqq, position and warning . There are different versions of these ahadith, and the following two are the most relevant to the Shia argument for Ali . </P>

Who took over the islamic empire after the caliphs