(4) باب مَا جَاءَ فِي بُيُوتِ أَزْوَاجِ النَّبِيِّ صلى الله عليه وسلم، وَمَا نُسِبَ مِنَ الْبُيُوتِ إِلَيْهِنَّ
Narrated `Abdullah bin `Umar:
Once I went upstairs in Hafsa's house and saw the Prophet (ﷺ) answering the call of nature with his back towards the Qibla and facing Sham.
Reference: Sahih al-Bukhari 3102
In-book reference: Book 57, Hadith 11
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 4, Book 53, Hadith 334