حَدَّثَنَا ابْنُ نُمَيْرٍ عَنِ الْأَعْمَشِ عَنْ إِبْرَاهِيمَ عَنْ عَلْقَمَةَ عَنْ عَبْدِ اللَّهِ قَالَ صَلَّى بِنَا رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَإِمَّا زَادَ وَإِمَّا نَقَصَ قَالَ إِبْرَاهِيمُ وَإِمَّا جَاءَ نِسْيَانُ ذَلِكَ مِنْ قِبَلِي فَقُلْنَا يَا رَسُولَ اللَّهِ أَحَدَثَ فِي الصَّلَاةِ شَيْءٌ قَالَ وَمَا ذَاكَ قُلْنَا صَلَّيْتَ قَبْلُ كَذَا وَكَذَا قَالَ إِنَّمَا أَنَا بَشَرٌ أَنْسَى كَمَا تَنْسَوْنَ فَإِذَا نَسِيَ أَحَدُكُمْ فَلْيَسْجُدْ سَجْدَتَيْنِ ثُمَّ تَحَوَّلَ فَسَجَدَ سَجْدَتَيْنِ
مسند امام احمد بن حنبل · Hadith 4032
It was narrated that 'Abdullah said: The Messenger of Allah (PBUH) led us in prayer, and he either added or omitted something. Ibraheem said: I am the one who forgot that. We said: O Messenger of Allah, has something been introduced into the prayer? He said: "Why is that?" We said: You just prayed such and such (number of rak'ahs). He said: i am only human and I forget as you forget. If one of you forgets something, let him prostrate twice." Then he turned around and prostrated twice.
Sanad
حَدَّثَنَا ابْنُ نُمَيْرٍ عَنِ الْأَعْمَشِ عَنْ إِبْرَاهِيمَ عَنْ عَلْقَمَةَ عَنْ عَبْدِ اللَّهِ