Language:
كتاب الصلاة
8  
Prayers (Salat)
(32)
Chapter: What has been said about (facing) the Qiblah (Kabah at Makkah) and wherever considered that there was no need to repeat the Salat (prayer) if someone offered prayers by mistake facing a direction other than that of the Qiblah
(32)
بَابُ مَا جَاءَ فِي الْقِبْلَةِ، وَمَنْ لاَ يَرَى الإِعَادَةَ عَلَى مَنْ سَهَا فَصَلَّى إِلَى غَيْرِ الْقِبْلَةِ
Sahih al-Bukhari 404

Narrated `Abdullah:

"Once the Prophet (ﷺ) offered five rak`at in Zuhr prayer. He was asked, "Is there an increase in the prayer?" The Prophet (ﷺ) said, "And what is it?" They said, "You have prayed five rak`at.' So he bent his legs and performed two prostrations (of Sahu).

حَدَّثَنَا مُسَدَّدٌ، قَالَ حَدَّثَنَا يَحْيَى، عَنْ شُعْبَةَ، عَنِ الْحَكَمِ، عَنْ إِبْرَاهِيمَ، عَنْ عَلْقَمَةَ، عَنْ عَبْدِ اللَّهِ، قَالَ صَلَّى النَّبِيُّ صلى الله عليه وسلم الظُّهْرَ خَمْسًا فَقَالُوا أَزِيدَ فِي الصَّلاَةِ قَالَ ‏ "‏ وَمَا ذَاكَ ‏"‏‏.‏ قَالُوا صَلَّيْتَ خَمْسًا‏.‏ فَثَنَى رِجْلَيْهِ وَسَجَدَ سَجْدَتَيْنِ‏.‏
Reference : Sahih al-Bukhari 404
In-book reference : Book 8, Hadith 56
USC-MSA web (English) reference : Vol. 1, Book 8, Hadith 398
  (deprecated numbering scheme)