Ghadir Khumm is one of the most important events in the history of Islam that took place in the final days of the blessed life of the Holy Prophet of Islam (PBUH). On the glory of this day it suffices to say that the Almighty God says: "This day I have perfected for you your religion and completed My favor upon you and have approved for you Islam as religion."
Therefore, Ghadir Khum is one of the greatest Islamic festivals because it is the day of the perfection of religion and completion of God's favor upon the Muslims, and because it is the day of introducing the Prophet's successor for leadership of the Islamic Ummah.
We have no intension of explaining the event of Ghadir Khum in detail; rather, we will bring and explain verses from the Holy Qur'an that have been descended on the occasion of this event. This is to refer to verses from Al-Maidah where the Almighty God says: "O Messenger, announce that which has been revealed to you from your Lord, and if you do not, then you have not conveyed His message. And Allah will protect you from the people. Indeed, Allah does not guide the disbelieving people."
The abovementioned verse attests to this fact that the Almighty God has revealed something to His Messenger that has been very difficult to announce, although the Messenger (PBUH) has been sent to proclaim it. It was the fact that Prophet (PBUH) should announce Imam Ali as his successor. And the Prophet did it.
Shia exegetes and theologians unanimously believe that the Verse of Proclamation is on the legitimate right to leadership and caliphate of Imam Ali (A.S).
source : www.tebyan.net
