Al-\لfi~ Abْ al-Fat< Mu<ammad b. `Alي al-Na>anzي related in "al-Kha#ل'i# al-`Alawiyyah" from al-\asan b. A<mad al-Muhrي [al-Muqrي] from A<mad b. `Abdallلh b. A<mad who said: Mu<ammad b. A<mad b. `Alي narrated to us, he said: Mu<ammad b. `Uthmلn b. Abي Shaybah narrated to us, he said: Ya<yل al-\immلnي narrated to us, he said: Qays b. al-Rabي` narrated to us from Abي Hلrْn al-`Abdي from Abي Sa`يd al-Khudrي who said:
The Messenger of Allلh, blessings and salutations of Allلh on him, summoned the people to `Alي, may Allلh be pleased with him, in Ghadيr Khumm. He gave instructions about the thorns under the tree and they were swept up. That was a Thursday. He called `Alي and took him by his upper arms and raised them up until the people saw the whiteness of the armpits of the Messenger of Allلh. They did not disperse until this verse was revealed: ‘Today I have perfected for you your religion...’ (5:3).
The Messenger of Allلh, blessings and salutations of Allلh on him, said: "Allلh is most Great at the perfection of religion and the completion of blessings, and the Lord’s acceptance of my mission and the mastership (wilلya) of `Alي, peace be upon him, after me."
Then he said: "Of whomsoever I am master (mawlل), `Alي is his master. O Allلh, 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."
\assلn said: "Permit me, O Messenger of Allلh, to recite some verses on `Alي for you to hear." He said: "Recite, with the blessing of Allلh."
So \assلn rose and said: "O elders of Quraysh, listen to my profession of the testimony of the Messenger of Allلh, blessings and salutations of Allلh on him, concerning the confirmed Wilلya:
On the day of al-Ghadيr 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 Wilلya.
He said to him: Rise, O `Alي, for I approve of you as Imلm and guide after me."
This <adيth has many chains of transmission leading up to Abu Sa`يd al-Khudrي.