The Prophet, blessings and salutations of Allah on him, summoned people to `Ali in Ghadir Khumm. He gave instructions about the thorns under the tree and they were swept up. That was a Thursday. He called `Ali and took him by his upper arms and raised them up until the people saw the whiteness of the armpits of the Messenger of Allah. They did not disperse until this verse was revealed: ‘Today I have perfected for you your religion...’ (5:3).

The Messenger of Allah, blessings and salutations of Allah on him, said: "Allah is most Great at the perfection of religion and the completion of blessings, and the Lord’s acceptance of my mission and the mastership (wilaya) of `Ali, peace be upon him, after me."

Then he said: "Of whomsoever I am master, `Ali is his master. O Allah, befriend one who befriends him and be at enmity with one who is hostile to him; help the one who helps him and forsake the one who forsakes him."

Hassan said: "Permit me, O Messenger of Allah, to recite some verses on `Ali for you to hear." He said: Recite, with the blessing of Allah."

So Hassan rose and said: "O elders of Quraysh, I follow it with my profession of the testimony of the Messenger of Allah concerning the mastership (wilaya) that is decreed." Then he recited:

"On the day of al-Ghadir their Prophet calls to them at Khumm, so listen to the Messenger calling;

He says: Who is your master and your guardian? They said, without displaying blindness there:

Your God is our Master and you are our guardian, and you will not find among us anyone disobedient concerning the Wilaya.

He said to him: Rise, O `Ali, for I approve of you as Imam and guide after me;

Of whomsoever I am master (mawla), then this is his guardian;

Be to him followers of truth, adhering;

Thereupon he called out: O Allah befriend his friend and to him who opposes `Ali, be at enmity."