Ibn Hibban

Hamzah bin Mughirah bin Shu'bah narrates from his father: The Prophet Muhammad (peace be upon him) stayed behind from the caravan. Sayyiduna Mughirah bin Shu'bah (may Allah be pleased with him) also stayed behind with him. When the Prophet Muhammad (peace be upon him) had relieved himself, he asked: "Do you have water?" I replied: "Yes, I do." I brought a water container to your service. The Prophet Muhammad (peace be upon him) washed both his hands and face. When he began to wash his arms, the sleeve of his cloak was tight, so he took his arm out from underneath and placed the cloak on his shoulder. Then he washed both his arms, then wiped over his socks and turban. Then he mounted (his ride), and I also mounted with him. We reached the people, and Sayyiduna Abdur Rahman bin Awf had already led them in one rak'ah (unit of prayer). When he sensed the arrival of the Prophet Muhammad (peace be upon him), he began to move back. But the Prophet Muhammad (peace be upon him) said: "Continue leading the prayer." When Sayyiduna Abdur Rahman bin Awf (may Allah be pleased with him) completed the prayer, the Prophet Muhammad (peace be upon him) and Sayyiduna Mughirah stood up and performed the rak'ah that they had missed earlier.