Sahih al-Bukhari 394
صحيح البخاري#394SahihNarrated Abu Aiyub Al-Ansari:The Prophet (ﷺ) said, "While defecating, neither face nor turn your back to the Qibla but face either east or west." Abu Aiyub added. "When we arrived in Sham we came across some lavatories facing the Qibla; therefore we turned ourselves while using them and asked for Allah's forgiveness
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: 8:46