Sahih Muslim Book: 6, Hadith: 1313

وَحَدَّثَنَا مِنْجَابُ بْنُ الْحَارِثِ التَّمِيمِيُّ، أَخْبَرَنَا ابْنُ مُسْهِرٍ، عَنِ الأَعْمَشِ، عَنْ إِبْرَاهِيمَ، عَنْ عَلْقَمَةَ، عَنْ عَبْدِ اللَّهِ، قَالَ صَلَّى رَسُولُ اللَّهِ صلى الله عليه وسلم فَزَادَ أَوْ نَقَصَ – قَالَ إِبْرَاهِيمُ وَالْوَهْمُ مِنِّي – فَقِيلَ يَا رَسُولَ اللَّهِ أَزِيدَ فِي الصَّلاَةِ شَىْءٌ فَقَالَ ‏ “‏ إِنَّمَا أَنَا بَشَرٌ مِثْلُكُمْ أَنْسَى كَمَا تَنْسَوْنَ فَإِذَا نَسِيَ أَحَدُكُمْ فَلْيَسْجُدْ سَجْدَتَيْنِ وَهُوَ جَالِسٌ ‏”‏ ‏.‏ ثُمَّ تَحَوَّلَ رَسُولُ اللَّهِ صلى الله عليه وسلم فَسَجَدَ سَجْدَتَيْنِ ‏.‏ ‘Abdullah (b. Mas’ud) reported:The Messenger of Allah (may peace be upon him) said prayer and he omitted or committed (something). Ibrahim (one of the narrators of this hadith) said: It is my doubt, and it was said: Messenger of Allah, has there been any addition to the prayer? He (the Holy Prophet) said: Verily I am a human being like you. I forget just as you forget so when any one of you forgets, he must perform...