Mishkat al-Masabih 480

God’s messenger relieved himself beside some low ground before the morning prayer, and I went with him carrying a small water-skin. When he came back I began to pour water from the skin over his hands, and he washed his hands and face. He was wearing a long-sleeved woollen gown, and tried to get his forearms out, but the sleeve of the gown was too narrow, so he brought his hands out from under the gown, and throwing it over his shoulders, he washed his forearms.

Then he wiped his forelock and over his turban. I was then about to remove his shoes when he said, “Leave them, for my feet were pure when I put them in”; so he rubbed over them, and he and I mounted our beasts and came to the people. They had begun the prayer with Abd ar-Rahman ibn Auf leading them, and he had performed a raka with them, but when he was aware of the Prophet’s presence he began to retire.

The Prophet (sallallahu alayhi wa sallam), however, signed to him to continue and performed one of the rakas along with him. Then when he had pronounced the salutation the Prophet (sallallahu alayhi wa sallam) got up, and I got up along with him, and we performed the raka which had been finished before we came.