Event of Ghadir after hajj al-tamattu’

Event of Ghadir
Main article: Event of Ghadir
In 10/632, the Prophet (s) decided, for the first time after migration, to perform hajj al-tamattu’.He informed the Muslims of his decision, and many of them decided to accompany him on the pilgrimage. The Prophet (s) also wrote a letter to Ali (a), who was on an expedition to Yemen, and called him to hajj.
When the hajj ended, on the way back to Medina, in an area called Ghadir Khumm, where people would part and go to their respective towns. God commanded the Prophet (s) to stop and proclaim to the people the message that He had given him.
The Prophet (s) performed the noon prayer and then delivered a sermon. In his sermon, he asked the Muslims, “Do you not know that I am closer to the believers than their own soul?The people said, “Yes indeed, we know.” Then the Prophet (s) raised the hand of Ali (a) and stated, “For whomever I am the master, Ali will be his master. O God! Support whomever supports him, and be the enemy of whomever shows enmity to him.

It is reported that some of the Companions asked the Prophet, “Is this the command of God and His Prophet (s)?” and the Prophet answered, “Yes, this is the command of God and His messenger.” When Prophet Muhammad (s) finished his sermon, a number of Companions, such as Umar b. Khattab, congratulated Ali (a).
According to Shiite and some Sunni commentators, the verse “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) was revealed on this day.
After the demise of the Prophet (s), Imam Ali (a) reminded the people of this event on several occasions and of the sayings of the Prophet (s) in Ghadir Khumm to emphasize his right to caliphate. Considering the context and the details of this event and other evidence (including the subsequent conversations and poems related to the event), the Shia believe that the message that the Prophet (s) delivered on the day of Ghadir was clearly the appointment of Imam Ali (a) as his successor by God’s command.