Hadith 1226 - Forgetfulness in Prayer - Sahih Al-Bukhari - صحيح البخاري - Collection of Actions, Sayings and Teachings of Prophet Muhammad (صلى الله عليه و سلم) - Kutub as-Sittah

22. Forgetfulness in Prayer - كتاب السهو

2) Chapter: If one offers five Rak'a (instead of four)

Narrated' `Abdullah:

Once Allah's Messenger (ﷺ) offered five rak`at in the Zuhr prayer, and somebody asked him whether there was some increase in the prayer. Allah's Messenger (ﷺ) said, "What is that?" He said, "You have offered five rak`at." So Allah's Messenger (ﷺ) performed two prostrations of Sahu after Taslim.

Reference: 1226
English reference: Vol. 2, Book 22, Hadith 317
In-book reference: Book 22, Hadith 3
Grade: Sahih
Read this hadith from Darussalam Collection

2) باب إِذَا صَلَّى خَمْسًا

حَدَّثَنَا أَبُو الْوَلِيدِ، حَدَّثَنَا شُعْبَةُ، عَنِ الْحَكَمِ، عَنْ إِبْرَاهِيمَ، عَنْ عَلْقَمَةَ، عَنْ عَبْدِ اللَّهِ ـ رضى الله عنه ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم صَلَّى الظُّهْرَ خَمْسًا فَقِيلَ لَهُ أَزِيدَ فِي الصَّلاَةِ فَقَالَ ‏‏‏.‏ قَالَ صَلَّيْتَ خَمْسًا‏.‏ فَسَجَدَ سَجْدَتَيْنِ بَعْدَ مَا سَلَّمَ‏.‏ "‏ وَمَا ذَاكَ ‏"