Musannaf Ibn Abi Shayba 1:1856

Hushaym narrated to us, he said: Husayn informed us, from Salim ibn Abi al-Ja'd and from Abu Sufyan, that they both heard al-Mughira ibn Shu'ba narrating. He said: I was with the Messenger of Allah on a journey, and he went out to relieve himself. When he finished, I came to him with a water skin containing water, and I poured it upon him. He was wearing a cloak with tight sleeves. He said: So he brought his hand out from under the cloak and washed his forearms, and wiped over his leather socks.