Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
nasai-kubra:1180 – Muḥammad b. Rāfiʿ > Yaḥyá b. Ādam > Mufaḍḍal / Ibn Muhalhil > al-Ḥasan b. ʿUbaydullāh > Ibrāhīm b. Sūwayd > Ṣallá ʿAlqamah Khams Faqīl Lah > Mā Faʿalt > Biraʾsī Balá > Waʾant Yā Aʿwar > Naʿam Fasajad Sajdatayn Thum > ʿAbdullāh

[Machine] It is narrated that the Prophet ﷺ performed five prayers and some people whispered to each other, saying, "Should we increase in our prayers?" He said, "No." So they informed him, and he then bent his legs and made two prostrations and said, "I am only a human being; I forget as you forget."  

الكبرى للنسائي:١١٨٠ – أَخْبَرَنَا مُحَمَّدُ بْنُ رَافِعٍ حَدَّثَنَا يَحْيَى بْنُ آدَمَ حَدَّثَنَا مُفَضَّلٌ وَهُوَ ابْنُ مُهَلْهِلٍ عَنِ الْحَسَنِ بْنِ عُبَيْدِ اللهِ عَنْ إِبْرَاهِيمَ بْنِ سُوَيْدٍ قَالَ صَلَّى عَلْقَمَةُ خَمْسًا فَقِيلَ لَهُ فَقَالَ مَا فَعَلْتُ؟ فَقُلْتُ بِرَأْسِي بَلَى قَالَ وَأَنْتَ يَا أَعْوَرُ؟ فَقُلْتُ نَعَمْ فَسَجَدَ سَجْدَتَيْنِ ثُمَّ حَدَّثَنَا عَنْ عَبْدِ اللهِ

عَنِ النَّبِيِّ ﷺ أَنَّهُ صَلَّى خَمْسًا فَوَسْوَسَ الْقَوْمُ بَعْضُهُمْ إِلَى بَعْضٍ فَقَالُوا لَهُ أَزِيدَ فِي الصَّلَاةِ؟ فَقَالَ «لَا» فَأَخْبَرُوهُ فَثَنَى رِجْلَيْهِ فَسَجَدَ سَجْدَتَيْنِ ثُمَّ قَالَ «إِنَّمَا أَنَا بِشْرٌ أَنْسَى كَمَا تَنْسَوْنَ»  

See similar narrations below:

Collected by Nasāʾī
nasai:1256 – Muḥammad b. Rāfiʿ > Yaḥyá b. Ādam > Mufaḍḍal b. Muhalhal > al-Ḥasan b. ʿUbaydullāh > Ibrāhīm b. Sūwayd > Ṣallá ʿAlqamah Khams Faqīl Lah > Mā Faʿalt > Biraʾsī Balá > And ʾAnt Yā Aʿwar > Naʿam Fasajad Sajdatayn Thum > ʿAbdullāh

"Alqamah prayed five (rak'ahs) and was told about that. He said: 'Did I really do that?' I nodded yes. He said: 'What about you, O odd-eyed one?' I said: 'Yes'. So he prostrated twice, then he narrated to us from 'Abdullah that the Prophet ﷺ prayed five (rak'ahs), and the people whispered to one another, then they said to him: 'Has something been added the prayer?' He said: 'No.' So they told him, and he turned around and prostrated twice, then he said: 'I am only human; I forget as you forget.'"  

النسائي:١٢٥٦ – أَخْبَرَنَا مُحَمَّدُ بْنُ رَافِعٍ قَالَ حَدَّثَنِي يَحْيَى بْنُ آدَمَ قَالَ حَدَّثَنَا مُفَضَّلُ بْنُ مُهَلْهَلٍ عَنِ الْحَسَنِ بْنِ عُبَيْدِ اللَّهِ عَنْ إِبْرَاهِيمَ بْنِ سُوَيْدٍ قَالَ صَلَّى عَلْقَمَةُ خَمْسًا فَقِيلَ لَهُ فَقَالَ

مَا فَعَلْتُ قُلْتُ بِرَأْسِي بَلَى قَالَ وَأَنْتَ يَا أَعْوَرُ فَقُلْتُ نَعَمْ فَسَجَدَ سَجْدَتَيْنِ ثُمَّ حَدَّثَنَا عَنْ عَبْدِ اللَّهِ عَنِ النَّبِيِّ ﷺ أَنَّهُ صَلَّى خَمْسًا فَوَشْوَشَ الْقَوْمُ بَعْضُهُمْ إِلَى بَعْضٍ فَقَالُوا لَهُ أَزِيدَ فِي الصَّلاَةِ قَالَ لاَ فَأَخْبَرُوهُ فَثَنَى رِجْلَهُ فَسَجَدَ سَجْدَتَيْنِ ثُمَّ قَالَ إِنَّمَا أَنَا بَشَرٌ أَنْسَى كَمَا تَنْسَوْنَ