We reached the people and found that they had already begun the prayer, with Abdul-Rahman bin Awf leading them. He had completed one cycle with them. When he sensed the Prophet's ﷺ presence, he started to step back, but the Prophet ﷺ gestured to him to continue.When he gave the closing salam, the Prophet ﷺ stood up, and I stood with him, and we performed the cycle that we had missed.
فانتهينا إلى القوم وقد قاموا في الصلاة، يصلي بهم عبد الرحمن بن عوف، وقد ركع بهم ركعة، فلما أحس بالنبي ﷺ، ذهب يتأخر، فأومأ إليه، فلما سلم قام النبي ﷺ، وقمت فركعنا الركعة التي سبقتنا.
Muslim narrated it in the Book of Purification (274-81), from Muhammad bin Abdullah bin Bazi, who said, Yazid (meaning Ibn Zuray) narrated to us, who said, Humayd Tawil narrated to us, who said, Bakr bin Abdullah Muzani narrated to us, from Urwa bin Mughira bin Shuba, from his father, and he related it.