Jami` at-Tirmidhi 8
جامع الترمذي#8SahihAbu Ayyub Al-Ansari narrated that :Allah's Messenger said: "When one of you arrives to defecate, then let none of you face the Qiblah while defecating, nor while urinating. And do not have your back towards it, but have it east of you or west of you
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih - Agreed Upon
In-book reference: 1:8