Zurarah bin Awfa and al-Hasan al-Basri (may Allah have mercy on them both) narrate that Mughirah bin Shu'bah (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) stayed behind (the caravan), and I stayed behind with him (peace and blessings be upon him). He (peace and blessings be upon him) relieved himself, and I brought him (peace and blessings be upon him) a vessel of water for purification. He (peace and blessings be upon him) performed ablution: he washed his face and wanted to wash his arms. He (peace and blessings be upon him) was wearing a Syrian jubbah with tight sleeves, so he (peace and blessings be upon him) brought his hands out from under the jubbah and washed his face and forearms, and wiped over his turban and his leather socks. Then we came to the people while Abdur-Rahman bin Awf (may Allah be pleased with him) was leading them in the Fajr prayer. When he saw the Prophet (peace and blessings be upon him), he wanted to step back, but he (peace and blessings be upon him) gestured to him to continue his prayer. So the Messenger of Allah (peace and blessings be upon him), and I with him (peace and blessings be upon him), prayed one rak'ah behind Abdur-Rahman bin Awf (may Allah be pleased with him). When he completed his prayer, the Messenger of Allah (peace and blessings be upon him) stood up and prayed one more rak'ah to complete it, and added nothing more to it.
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 18175