Abu Huraira reported God’s Messenger as saying, “When you come to the prayer and we are prostrating ourselves you must prostrate yourselves without reckoning it as part of your prayer; and if anyone is present at a <i>rak'a</i> he has been present at the prayer.” Abu Dawud transmitted it.

وَعَنْ أَبِي هُرَيْرَةَ رَضِيَ اللَّهُ عَنْهُ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِذَا جِئْتُمْ إِلَى الصَّلَاةِ وَنَحْنُ سُجُودٌ فَاسْجُدُوا وَلَا تَعُدُّوهُ شَيْئًا وَمَنْ أَدْرَكَ رَكْعَةً فقد أدْرك الصَّلَاة» . رَوَاهُ أَبُو دَاوُد