It is narrated from Sayyiduna Zayd bin Arqam (may Allah be pleased with him) that when the Messenger of Allah (peace and blessings be upon him) returned from the Farewell Pilgrimage and halted at the place called Ghadir Khumm, he (peace and blessings be upon him) gave orders concerning some large, shady trees, and the ground beneath them was cleared. Then he (peace and blessings be upon him) said: "It seems to me that I will soon be called (by my Lord) and I shall respond. I am leaving among you two weighty things (al-thaqalayn), one of which is greater than the other: the Book of Allah Almighty and my family ('itrah, the Ahl al-Bayt). So see how you treat these two after me, for they will never separate from one another until they come to me at the Pond (al-Kawthar)." Then he (peace and blessings be upon him) said: "Indeed, Allah, the Mighty and Majestic, is my Master (Mawla), and I am the guardian (wali) of every believer." Then he (peace and blessings be upon him) took hold of the hand of Sayyiduna Ali (may Allah be pleased with him) and said: "Whoever I am the wali (friend and patron) of, then this one (Ali) is his wali. 'Allahumma wali man walahu, wa 'adi man 'adahu' (O Allah! Befriend whoever befriends him, and be hostile to whoever is hostile to him)." And after that the narrator mentioned the lengthy hadith. This hadith is sahih (authentic) on the condition of Imam Bukhari and Imam Muslim, but they did not record it at this length. The narration of Salamah bin Kuhayl from Abu al-Tufayl, which is a supporting witness (shahid) for this hadith, is also sahih on the condition of the two of them:

It is narrated from Sayyiduna Zayd bin Arqam (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) halted between Makkah and Madinah near five large, shady trees. The people cleared the ground beneath those trees. Then, in the evening, the Messenger of Allah (peace and blessings be upon him) led the prayer and stood to deliver a sermon; he praised and extolled Allah, gave admonition and exhortation, and said whatever Allah willed. Then he (peace and blessings be upon him) said: "O people! I am leaving among you two things; if you follow them you will never go astray: the Book of Allah and my Ahl al-Bayt, that is, my family ('itrah)." Then he (peace and blessings be upon him) asked three times: "Do you know that I have a greater claim (priority) over the believers than they have over themselves?" The Companions said: Yes! So the Messenger of Allah (peace and blessings be upon him) said: "Whoever I am the mawla (friend and helper) of, Ali is his mawla." And the hadith of Buraydah al-Aslami (may Allah be pleased with him) is also sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim).

It is narrated from Sayyiduna Buraydah al-Aslami (may Allah be pleased with him) that he said: I took part in the campaign to Yemen with Sayyiduna Ali (may Allah be pleased with him), and I sensed (as I thought) some harshness from him. Then, when I came into the presence of the Messenger of Allah (peace and blessings be upon him), I mentioned Sayyiduna Ali (may Allah be pleased with him) and made some complaint about him, whereupon I saw the colour of the blessed face of the Messenger of Allah (peace and blessings be upon him) change. He (peace and blessings be upon him) said: "O Buraydah! Do I not have a greater claim (priority) over the believers than they have over themselves?" I said: Certainly, O Messenger of Allah! He (peace and blessings be upon him) said: "Whoever I am the mawla of, Ali is his mawla." And after that the narrator mentioned the complete hadith. This hadith is sahih (authentic) on the condition of Imam Muslim, but the two Shaykhs did not record it.

It is narrated from Sayyiduna Imran bin Husayn (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) sent out a military detachment and appointed Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) as its commander. Sayyiduna Ali (may Allah be pleased with him) set out on that expedition and took a slave girl (from the spoils), which the Companions objected to, and four Companions of the Messenger of Allah (peace and blessings be upon him) made a pact among themselves: when we meet the Messenger of Allah (peace and blessings be upon him), we will tell him about what Ali (may Allah be pleased with him) has done. Sayyiduna Imran (may Allah be pleased with him) says: It was the custom of the Muslims that when they returned from a journey, they would first present themselves before the Messenger of Allah (peace and blessings be upon him) and greet him with salam, and then go to their lodgings. So when this detachment returned, they greeted the Messenger of Allah (peace and blessings be upon him) with salam. Then the first of those four stood up and said: O Messenger of Allah! Have you not seen that Ali did such and such? He (peace and blessings be upon him) turned away from him. Then the second stood up and said the same thing, and he (peace and blessings be upon him) turned away from him too. Then the third stood up and said the same thing, and he (peace and blessings be upon him) turned away from him too. Then when the fourth stood up and also said the same thing, the Messenger of Allah (peace and blessings be upon him) turned towards him, with signs of anger on his (peace and blessings be upon him) blessed face, and said: "What do you people want from Ali? Indeed, Ali is from me and I am from him, and he is the wali (patron and friend) of every believer." This hadith is sahih (authentic) on the condition of Imam Muslim, but the two Shaykhs did not record it.

It is narrated from Muhammad bin Ishaq that when Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) accepted Islam, his blessed age was ten years.

It is narrated from Qatadah that al-Hasan al-Basri said: "When Sayyiduna Ali (may Allah be pleased with him) accepted Islam, his age was fifteen or sixteen years." Imam al-Hakim said: This chain is better and more reliable than the first chain, and I placed that (previous narration) first only because its chain was elevated ('ali, with fewer narrators).

Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said: "Sayyiduna Ali (may Allah be pleased with him) has four distinctions that no one else has: he is the first of the Arabs and non-Arabs to pray with the Messenger of Allah (peace and blessings be upon him); in every battle the banner of the Messenger of Allah (peace and blessings be upon him) was with him; he stood firm with him (peace and blessings be upon him) on the day of Uhud (the Day of al-Mihras); and it was he who washed him (peace and blessings be upon him) and laid him in his blessed grave."

It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) gave the banner to Sayyiduna Ali (may Allah be pleased with him) on the day of Badr, when he was twenty years old. This hadith is sahih (authentic) on the condition of Imam Bukhari and Imam Muslim, but they did not record it.

It is narrated from Sayyiduna Ali (may Allah be pleased with him) that he said: "I am the servant of Allah and the brother of His Messenger, and I am al-Siddiq al-Akbar (the greatest affirmer of truth); no one after me will make this claim except a liar. I prayed seven years before the people." This hadith is sahih (authentic) on the condition of Imam Bukhari and Imam Muslim, but they did not record it, and it is supported by this hadith:

It is narrated from Sayyiduna Ali (may Allah be pleased with him) that he said: "I began worshipping Allah Almighty together with the Messenger of Allah (peace and blessings be upon him) seven years before any other member of this Ummah worshipped Him."