حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ حَدَّثَنَا شُعْبَةُ قَالَ كَتَبَ إِلَيَّ مَنْصُورٌ وَقَرَأْتُهُ عَلَيْهِ قَالَ حَدَّثَنِي إِبْرَاهِيمُ عَنْ عَلْقَمَةَ عَنْ عَبْدِ اللَّهِ قَالَ صَلَّى رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ صَلَاةً لَا أَدْرِي زَادَ أَمْ نَقَصَ إِبْرَاهِيمُ الْقَائِلُ لَا يَدْرِي عَلْقَمَةُ قَالَ زَادَ أَوْ نَقَصَ أَوْ عَبْدُ اللَّهِ ثُمَّ اسْتَقْبَلَنَا فَحَدَّثْنَاهُ بِصَنِيعِهِ فَثَنَى رِجْلَهُ وَاسْتَقْبَلَ الْقِبْلَةَ وَسَجَدَ سَجْدَتَيْنِ ثُمَّ أَقْبَلَ عَلَيْنَا بِوَجْهِهِ فَقَالَ لَوْ حَدَثَ فِي الصَّلَاةِ شَيْءٌ لَأَنْبَأْتُكُمُوهُ وَلَكِنْ إِنَّمَا أَنَا بَشَرٌ أَنْسَى كَمَا تَنْسَوْنَ فَإِنْ نَسِيتُ فَذَكِّرُونِي وَأَيُّكُمْ مَا شَكَّ فِي صَلَاتِهِ فَلْيَتَحَرَّ أَقْرَبَ ذَلِكَ لِلصَّوَابِ فَلْيُتِمَّ عَلَيْهِ وَيُسَلِّمْ ثُمَّ يَسْجُدْ سَجْدَتَيْنِ
مسند امام احمد بن حنبل · Hadith 4174
It was narrated that 'Abdullah said: The Messenger of Allah (PBUH) offered the prayer and I do not know whether he added or omitted something. Then he turned to face us and we told him what he had done, so he turned to face the qiblah and prostrated twice, then he turned to face us and said: "If something had been introduced into the prayer, i would have told you. But I am only human and i forget as you forget, so if i forget then remind me. And if any of you has any doubts concerning his prayer, let him think of what is most likely to be the case and then complete (his prayer on that basis) and say the s almn, then prostrate twice."
Sanad
حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ حَدَّثَنَا شُعْبَةُ قَالَ كَتَبَ إِلَيَّ مَنْصُورٌ وَقَرَأْتُهُ عَلَيْهِ قَالَ حَدَّثَنِي إِبْرَاهِيمُ عَنْ عَلْقَمَةَ عَنْ عَبْدِ اللَّهِ