Musnad Ahmad 619:1

'Affan narrated to us, Yahya bin Sa'id narrated to us, he said: Abu Ja'far 'Umayr bin Yazid narrated to me, Al-Harith bin Fudayl and 'Umarah bin Khuzaymah bin Thabit narrated to me, from 'Abd al-Rahman bin Abi Qurad, he said: "I went out with the Prophet, peace and blessings of Allah be upon him, for Hajj." He said: "I saw him come out from the privy, so I followed him with a water skin or a vessel. And the Messenger of Allah, peace and blessings of Allah be upon him, when he wanted to relieve himself, he would go far away. So I sat for him on the path until the Messenger of Allah, peace and blessings of Allah be upon him, returned. I said to him: 'O Messenger of Allah, [here is] water for ablution.' He said: 'So the Messenger of Allah, peace and blessings of Allah be upon him, came toward me and poured [water] onto his hand and washed it. Then he inserted his hand and cupped it, then he poured [water] onto one hand. Then he wiped his head. Then he took a handful of water with his hand and struck it upon the top of his foot, and wiped his foot with his hand. Then he came and led us in the Dhuhr prayer.'"