An important day in Islamic History.
On 18th of Dhul-hijjah of the year 10 A.H. (10 March 632 CE), after completing the last pilgrimage, the Holy Prophet (peace and blessings be upon him and his family) along with around 100,000 Muslims reached a place called 'Ghadir-e-Khumm' near Mecca. The following verse was revealed : O Messenger! Deliver what has been revealed to you from your Lord; and if you do it not, then you have not delivered His message, and Allah will protect you from the people; surely Allah will not guide the unbelieving people. [Quran 5:67]
The Messenger of Allah declared: “It seems the time has approached when I shall be called away (by Allah) and I shall answer that call. I am leaving for you two precious things and if you adhere both of them, you will never go astray after me. They are the Book of Allah and my progeny, that is my Ahlul-Bayt. The two shall never separate from each other until they come to me by the Pool (of Paradise).”
Then the Messenger of Allah continued: “Do I not have more right over the believers than what they have over themselves?”People cried and answered: "Yes, O’ Messenger of God.”Then Prophet (S) held up the hand of ‘Ali and said: "Whoever I am his leader (Mawla), ‘Ali is his leader (Mawla). O’ God, love those who love him, and be hostile to those who are hostile to him.”
Some of the Sunni references:
(1) Sahih Tirmidhi, v2, p298, v5, p63
(2) Sunan Ibn Maja, v1, pp 12,43
(3) Khasa’is, by al-Nisa’i, pp 4,21
(4) al-Mustadrak, by al-Hakim, v2, p129, v3, pp 109-110,116,371
(5) Musnad Ahmad Ibn Hanbal, v1, pp 84,118,119,152,330, v4, pp 281,368,370, 372,378, v5, pp 35,347,358,361,366,419 (from 40 chains of narrators)
(6) Fada’il al-Sahaba, by Ahmad Hanbal, v2, pp 563,572
(7) Majma’ al-Zawa’id, by al-Haythami, v9, p103 (from several transmitters)
(8) Tafsir al-Kabir, by Fakhr al-Razi, v12, pp 49-50
(9) Tafsir al-Durr al-Manthur, by al-Hafiz Jalaluddin al-Suyuti, v3, p19
(10) Tarikh al-Khulafa, by al-Suyuti, pp 169,173
"Because love for Ali is faith, and hate for him is disbelief. But rather, the Paradise was created for the people of faith, and the Fire was created for the people of disbelief. Therefore, he is the distributor of the Paradise and the Fire due to this reason. So the Paradise, none shall enter it except the people who love him, and the Fire, none shall enter except for the people who hate him."
— Imam Jafar al-Sadiq (ع) Illal al-Sharaie v. 1, ch. 130
