The Holy Prophet of Islam, Muhammad ibni Abdullah (s.a.w) went to Mecca in the last year of his life to perform the worship of "Hajj". He also invited all the Muslims to take part in the Hajj ceremonies, and, in response to his invitation, all those who were able to do so accepted the Prophet's dictate. In a short while, large numbers of Muslims were moving towards Mecca. There they performed the glorious worship of Hajj and learned from the Prophet all its customs and procedures.
When the ceremonies of the Hajj and the visits to the Holy Ka'aba were over, the caravans made ready their return and set off. The Prophet, too, accompanied a caravan and set off for Medina.
The sound of the camel bells had filled the desert. The weather was hot and the desert scalding. Mid-journey, God's angel of revelation descended and brought the Prophet this message from God:
"O Prophet! Deliver to mankind the message that has descended to you from your Lord. If you do it not, you have not fulfilled your Divine mission. God will guard you from the evil of mankind and will not make the unbelievers successful."
At that very spot, the Prophet dismounted to carry out the Divine command. He called to a group of Muslims and told them to tell all the caravans that had advanced to come back, and to tell those that hadn't yet arrived to hurry up.
This group quickly mounted their camels and hastily reached the caravans which were advancing and tey called out loudly, "Stop! Stop! Come back! Come back!"
The men of the caravans pulled at the bridles of their camels and the ringing of the bells stopped. One by one they asked, "Why must we stop? What has happened? Why must we stop in this heat? Why return?"
The riders told them that the Prophet had commanded them to return and come to him at the side of the pool-called Ghadeer .
The caravans returned and arrived at the side of the pool, and those that hadn't yet come also arrived. In this way thousands of Muslims who were on their return from the Hajj all gathered at Ghadeer of the 18th day of the month of Zill Hijjah and offered the Zohr (noon) prayer with the Holy Prophet (s.a.w).
Then they built a platform of camel saddles and luggage and the Holy Prophet stood on the top in order to carry out the Divine command and deliver to the people that important message.
The people were all silent and still, waiting to hear the Prophet's speech, and to know what the "important message" was.
After a very eloquent speech, the Prophet asked the people in a loud voice and heavenly tone, "O people! Who is your guide and guardian? Who is your leader and ruler? Am I not your leader and your guide? Am I not your guardian and ruler?
They replied, "O Prophet of God, you are our leader and ruler. You are our guide."
Then the Holy Prophet called for Ali ibne Abi Talib and gave him a place next to himself. He took his hand and held it aloft, showing this to the people, and in his loudest voice and most glorious tones he commanded:
"Those whose guide and leader I am, after me, will be guided and led by Ali. O people! O Muslims! After me, Ali is your guide and master".
Then he lifted his hands to the skies and said: "Lord! Be friendly with the friends of Ali! Be an enemy to the enemies of Ali! Lord! Help the helpers of Ali, and humble those that wish evil of Ali!"
Then he descended from the platform, wiped the sweat from his forehead, took a deep breath, stood still for a moment, and commanded the Muslims to, "Make allegiance to my brother and successor; congratulate him on his Divine appointment. He is Imam and Amir ul-Mumineen .
In this way, on the 18th day of the month of Zill Hijjah, Ali ibne Abi Talib was selected for leadership and Imamate. The position of leadership and Imamate became part of religion, and with the introduction of leadership, the religion of Islam became perfect and eternal. In this way, God entrusted the guardianship and leadership of the Muslims to the twelve Imams. And, in the age of the Imam's absence, a virtuous courageous and aware master of the Divine law (Mujtahid), who also has the capacity to manage, becomes the representative and successor of the Imam, guiding the Islamic society their political, social and religious affairs while the people accept his guidances and ordinances with relief and gratitude.
Every year, we make this great day a festival and become happy due to the Imamate of Imam Ali (a.s). We recognise Ali as Imam and leader of the Muslims and we strive to follow him in words and deeds.