Sahih al-Bukhari 145
صحيح البخاري#145SahihNarrated `Abdullah bin `Umar:People say, "Whenever you sit for answering the call of nature, you should not face the Qibla or Baitul-Maqdis (Jerusalem)." I told them, "Once I went up the roof of our house and I saw Allah's Apostle answering the call of nature while sitting on two bricks facing Baitul-Maqdis (Jerusalem) (but there was a screen covering him. ' (Fath-al-Bari, Page 258, Vol)
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 4:11