Furthermore he had been specially singled out by the Prophet...

Furthermore he had been specially singled out by the Prophet from among (all) his relations because of (the qualities) which no other relation, apart from him, shared with the Prophet and because of the nomination (nass) of his authority (wilaya) by God, may God be magnified and exalted, in the Qur'an where He, may His name be exalted, says: Your authority (wali) is God and His Apostle and those believers who perform the prayer and pay alms (zakat) while they are bowing (in prayer).

(v 55) It is known that no one except him paid alms while bowing (in prayer). It has been established in language that wali means "the most appropriate for authority" (awla), without there being any opposition (to this definition). If the Commander of the faithful, peace be on him, was, by the stipulation of the Qur'an, more appropriate for authority among the people than themselves because of his being their war according to the textual nomination (nass) in the Clear Explanation (i.e.

the Qur'an, tibyan). it was obviously necessary for all of them to obey him, just as obedience to God, the Most High, and obedience to His Apostle, peace be on him and his family, was required because of the information about their authority (wilaya) over creatures which is given in this verse with clear proof. (Another reason for their support for the Commander of the faithful was) because of what the Prophet, may God bless him and his family, said on the day (of the assembly) at his house.

He had especially gathered the Banu 'Abd al-Muttalib there in order to make the (following) solemn pledge: "Whoever helps me in this matter will be my brother, my testamentary trustee (wasi), my helper (wazir), my heir and my successor after me." Then the Commander of the faithful, peace be on him, stood up before him among all the gathering of them, and on that day he was the youngest of them, and he said: "O Apostle of God, I will help you." Then the Prophet, may God bless him and his family, said: "Sit down, you are my brother, my trustee, my helper, my inheritor and successor after me." This is a clear statement about the succession (after the Prophet).

In addition, there is also what (the Prophet), peace be on him and his family, said on the day of Ghadir Khumm. The community had gathered to listen to the sermon (in which he asked): "Am I not more appropriate for authority (awla) over you than yourselves?" "Yes," they answered.