Sahih Muslim Book 7, Hadith Number 2977.

Chapter : Excellence of flinging pebbles at Jamrat al-Aqaba on the day of sacrifice (10th of Dhu’l-Hijja) while riding.

Umm al-Husain (Allah be pleased with her) reported: I performed Hajj along with Allah’s Messenger (may peace be upon him) on the occasion of the Farewell Pilgrimage and saw him when he flung pebbles at Jamrat al-‘Aqaba and returned while he was riding the camel, and Bilal and Usama were with him. One of them was leading his camel, while the other was raising his cloth over the head of Allah’s Messenger (may peace be upon him) to protect him from the sun. She (further) said: Allah’s Messenger (may peace be upon him) said so many things, and I heard him saying: If a slave having some limb of his missing and having dark complexion is appointed to govern you according to the Book of Allah the Exalted, listen to him and obey him.