Who among you will assist me on this mission and become my brother...
Who among you will assist me on this mission and become my brother, executor, and successor?" No one accepted the invitation, and I said: "Messenger of God, I shall be your assistant." He held my neck and said to them: "This is my brother, executor, and successor. Listen to him and obey him." They laughed, saying to Abu Talib: He (Muhammad) commanded you to listen to your son and to obey him.
( al-Tabari , al-Ta'rikh, part 2, pages 319-21) This hadith was reported by Ibn Ishaq, Ibn Abi Hatim, Ibn Mardawayh, and Al-Bayhaqi in his book aI-Dala'il. This was also reported by a number of historians including Abu al-Fida and Ibn al-Athir. In addition, Muhammad Hussein Haykal recorded it in his book Hayat Muhammad (first edition).
Here we should ask the following question: Imam Ali reported that the Messenger of God is the one who granted him the office of executorship, brotherhood, and successorship. Sayf Ibn 'Umar reported that the idea of the executorship of Ali had come from a Jew called Abdullah Ibn Saba. We should ask the members of the Takfeer University (who call everyone who disagrees with them "Kafir"-unbeliever) the following question: Do you believe Imam Ali's report or Sayf Ibn 'Umar's?
Sayf was accused by prominent Sunnite scholars of weakness, forgery, and heresy. Of course, we should not expect any true Muslim to choose the report of a liar such as Sayf Ibn 'Umar and reject the report of the Imam of the faithfuls, Ali Ibn Abi Talib, the brother of the Prophet.
The Messenger of God once said to Ali: "Would you not be pleased to be to me like Aaron was to Moses, but there shall be no Prophet after me?" (al-Bukhari in his Sahih reported this through his channel to Sa'd Ibn Abi Waqqas, part 6, page 3). Muslim also reported this in his Sahih , part 15, page 176.
Hadith Al-Ghadir Do the mercenary writers who endeavor to spread hostility among Muslims forget that while returning from his farewell pilgrimage, and in the presence of over a hundred thousand pilgrims, the Messenger of God declared: "Do I not have more right over the believers than they have over themselves?" "They answered: 'Yes, Messenger of God.' "The Prophet held up the hand of Ali and said: 'Whoever I am his Mawla (leader), this Ali is his Mawla.
God, love whoever loves him, and be hostile to whoever is hostile to him.' " No Muslim would doubt that the Messenger of God is the leader of all Muslims from all generations.