The Manners of Answering the Call of Nature Bulugh al-Maram 105

Arabic hadith text
وَعَنْ سُرَاقَةَ بْنِ مَالِكٍ ‏- رضى الله عنه ‏- قَالَ: { عَلَّمْنَا رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏-فِي اَلْخَلَاءِ:" أَنَّ نَقْعُدَ عَلَى اَلْيُسْرَى, وَنَنْصِبَ اَلْيُمْنَى"} رَوَاهُ اَلْبَيْهَقِيُّ بِسَنَدٍ ضَعِيف ٍ 1‏ .‏‏1 ‏- ضعيف.‏ رواه البيهقي (1/96)‏.‏
Translation
Narrated Suraqa bin Malik (rad)

Allah’s Messenger (ﷺ) educated us about lavatory (manners) that we should sit on our left foot and keep erect our right foot. [Reported by Al-Baihaqi through a chain of weak narrators].