Every eighteenth of Dhul-Hijjah is marked and celebrated world-wide by the Shia-Muslims as the Ghadir Khum festival. The day is a remarkable day in the history of Islam as the Apostle of God (Peace be upon him and his pure household) was commanded on this day in the tenth year after Hijrah to stop at the pond of Khumm with the sole aim of nominating Ali son of Abu-Talib (peace be upon him) as his vicegerent and the immediate successor after him. With this divine appointment, the religion of Islam was perfected and approved of by Allah and His favours were completed.
In the tenth year after Hijrah, the noble Prophet (PBUH) embarked on his last pilgrimage to Makka which is popularly referred to as the farewell pilgrimage (i.e. Hujjat al-Widah). On the eighteenth of Dhul-Hijjah while returning to Madina, the Prophet (PBUH) received Divine revelation at a place called Ghadir Khum (i.e. the pond of Khum). Ghadir Khum is situated at a place between Makkah and Madina; where the routes to Madina, Egypt and Iraq converged. The Divine message said,
“O Apostle! Communicate that which has been sent down to you from your Lord, and if you do not, you will not have communicated His message, and Allah shall protect you from the people. Indeed Allah does not guide the faithless lot.[i]” [Qur’an 5: 67]
Immediately after this revelation, the Messenger of God (PBUH) stopped all the caravans and delivered a historical sermon where he appointed Hazrat Ali (a.s) to be his successor and the leader of the Muslim community immediately after him. He declared: “...I am the Master (Mawla) of the faithful and whoever I am his Master, then, (this) Ali is his Master...”
According to reliable historical reports, several companions of the Prophet (PBUH) congratulated and gave oath of allegiance to Hazrat Ali (a.s). Thereafter, a gladtiding message was revealed to the Prophet (PBUH) saying: “...Today I have perfected your religion for you, and I have completed My blessing upon you, and I have approved Islam as your religion...” [Qur’an 5: 3]
From the above, it is obvious that the crucial message the Apostle of God was commanded to communicate to the Muslims under such an extreme heat and which if not delivered would have been tantamont to non-deliverance of his Prophetic mission was about the leadership of Hazrat Ali son of Abu-Talib (a.s). As a result and following this appointment, the religion (i.e. Islam) was perfected and approved of as the religion of salvation and the blessings of Allah were also completed upon the faithful.
Footnote:
[i] Jalaludeen Suyuti in his Durr al-Manthur, Fakhr Razi in his Tafsir al-Kabir, Waheedi Naysaburi in his Asbab al-Nuzul, Shawkani in his Fathu al-Ghadir, Abu al-Fath Shahristani in his Milal wa Nihal, and tens of other Sunni Quranic exegetes and historians clearly affirmed that this verse was revealed on the day of Ghadir Khumm in relation to the appointment of Ali (AS) as the Prophet’s vicegerent.