As-Sahw (forgetfulness) in prayer and prostrating to compensate for it
وَحَدَّثَنَا ابْنُ نُمَيْرٍ، حَدَّثَنَا ابْنُ إِدْرِيسَ، عَنِ الْحَسَنِ بْنِ عُبَيْدِ اللَّهِ، عَنْ إِبْرَاهِيمَ، عَنْ عَلْقَمَةَ، أَنَّهُ صَلَّى بِهِمْ خَمْسًا .
Alqama reported: He (the Holy Prophet) had led them five rak'ahs in prayer.