Musnad Ahmad 626:27

He said: I read to Abd al-Rahman: Malik, from Ibn Shihab, from Abbad ibn Ziyad, from the descendants of al-Mughirah ibn Shu'bah, from his father al-Mughirah, that the Messenger of Allah, peace and blessings of Allah be upon him, went to relieve himself during the expedition of Tabuk. Al-Mughirah said: So I went with him with water. The Messenger of Allah, peace and blessings of Allah be upon him, came, and I poured water over him. He washed his face, then he went to take his hands out from the sleeves of his jubbah (outer garment), but he could not because of the narrowness of the sleeves of the jubbah. So he brought them out from under his jubbah, and he washed his hands, wiped his head, and wiped over his leather socks. Then the Prophet, peace and blessings of Allah be upon him, arrived while Abd al-Rahman ibn Awf was leading them in prayer, and he had already prayed one rak'ah with them. The Messenger of Allah, peace and blessings of Allah be upon him, prayed the rak'ah that remained for them with them. When the Messenger of Allah, peace and blessings of Allah be upon him, finished, he said: "You have done well."