Prophet's Tribe, Ahlal Bayt (Family) & Righteous Successors
Why did Prophet Muhammad ﷺ say that and what did he mean?
The Prophet's relationship with Ali ibn Abi Talib (alaihi salaam) is unlike with anyone else from his family and companions. Ali (a.s) was not only the Prophet's first cousin and his son in law but in fact he is the only whom Allah ﷻ chose for Prophet's lineage to continue after his death even though the Prophet had 3 other daughters and son in laws. The Prophet ﷺ only chose Ali (a.s) to marry his most beloved daughter Fatimah (a.s) despite having proposals for her from his best companions Abu Bakr (r.a) and Umar (r.a). Hence Ali ibn abi Talib (a.s) has a very special status in Islam which all of us need to recognize.
A famous hadith narrated from the Prophet ﷺ says: “For whomever I am his Mawla then 'Ali is his Mawla.” Just like there is a background of every verse of the Quran similarly there is background of every prophetic hadith that needs to be kept in view to better comprehend their meaning. According to all historical narratives, those recorded in early Islamic history and those recorded in our times, mention that these words were declared after the prophet’s hajjatul wida (farewell or last pilgrimage) before his retirement to Madinah. He said them at a place called Ghadir e Khumm (pond of the khumm), a place between Makkah and Madinah. He said them in reference to the status of Ali ibn Abi Talib (alaihi salaam) for all to hear, loud and clear so they continue to deal with him in the manner as instructed especially after Prophet’s passing away. A year before his last hajj (pilgrimage), the Prophet ﷺ deputed Ali (a.s) to Yemen, as his representative to instruct and teach the people there about Islam. When the Prophet ﷺ was to begin his journey for the final hajj, he invited Ali and his followers to join him on this sacred journey. Some of Ali’s followers had disagreements with his orders and being the leader of their deputation they were supposed to obey him. Amr ibn Shaas al-Aslami complained about Ali (a.s) upon returning from Yemen where he had accompanied him. News of it reached the Prophet ﷺ who said: “O Amr! By Allah, you have done me harm.” Amr said, “I seek refuge in Allah from harming you, O Messenger of Allah!” He said “But you did. Whoever harms Ali harms me.” When the Prophet ﷺ came to know of this, he summoned a large gathering of pilgrims and ordered them to assemble for an important declaration. At this point the prophet said the above words “Ali is the Mawla of whom I am the Mawla. 0 God! Have friendship towards those who have friendship for Ali, and have enmity towards those who have enmity for Ali”. The word mawla has a wide range of meaning. It denotes ‘master’, ‘slave’, ‘emancipated slave’, ‘helper’, ‘friend’ and ‘loved one’. Without going in to further discussion of whether this was prophet’s declaration of Ali’s successorship or no, we need to look at what else the Prophet ﷺ predicted about Ali (a.s) which would help better understand this declaration.
The Prophet ﷺ had predicted Ali would fight the khawarij with the words: “In truth there will be, among you, one who shall fight over the interpretation of the Qur’an just as I fought over its revelation.” Abu Bakr and Umar asked: “Am I he?” The Prophet said: “No, it is the one who is mending the shoes.” He had given his shoes to Ali to mend. The Prophet ﷺ also predicted Ali’s martyrdom with the words: “This shall be dyed red from this” and he pointed to Ali’s beard and head respectively. Additionally the Prophet ﷺ had predicted the first fitna (first civil war) that would hit the Muslim nation after Uthman’s martyrdom and the battles that will take place between Ali (a.s) and the opponents. The Prophet ﷺ also predicted that it would be Ali (a.s) who would be on the right and the opposition on the wrong as discussed in detail in my post on Prophecy of Future Events. Since the transpiration of all those future events were already in the Prophet’s knowledge therefore this was the best opportunity to express Ali’s status especially when his authority was being challenged and it was the Prophet’s last hajj where all Muslims had gathered. Despite the fact that this declaration was not made at the center of hajj, in Makkah, yet the Prophet ﷺ ordered those who were absent to attend it so that they may witness should they live long enough to experience the future internal battles.
An important point to note here is that many apparently observe the Ghadir event in the light of great merits of Ali (a.s), without taking in to consideration all the future historical events surrounding his personality, and conclude that this incident must have been Prophet's declaration of Ali's successorship and leadership. However, what they fail to observe is that while Ali’s great importance was being stressed at Ghadir after the Prophet's own yet he did not explicitly command the Muslims about making him the leader. This incident was a reminder given to the audience and us about the merits of Ali (r.a), which are no doubt supreme, but does not say that he should or will become a leader. Prophet Muhammad ﷺ while declaring Ali as “mawla” does not refer to him a khaleefa, ameer or imaam of Muslims after him and this is obvious from his wordings.
 Jami Tirmidhi Vol. 1, Book 46, Hadith 3713 – Sunnah.com
 Abu Nuaym, Hilya al-Awliya 1:100-128 #4; al-Dhahabi, Siyar Alam al-Nubala 1/2:615-660 #5 - Nuaym, Abu. n.d. Ali Ibn Abi Talib (r). Accessed March 20, 2019. http://www.sunnah.org/publication/khulafa_rashideen/caliph4.htm - (Nuaym n.d.) &
The Event of Ghadir Khumm in the Qur'an, Hadith, History By Mohammad Manzoor Nomani - https://www.islamawareness.net/Deviant/Shia/ghadir.html
 First extremists in the history of Islam.
 &  Abu Nuaym, Hilya al-Awliya 1:100-128 #4; al-Dhahabi, Siyar Alam al-Nubala 1/2:615-660 #5 - Nuaym, Abu. n.d. Ali Ibn Abi Talib (r). Accessed March 20, 2019. http://www.sunnah.org/publication/khulafa_rashideen/caliph4.htm - (Nuaym n.d.)