Bulugh al-Maram, Book 1, Hadith 111 (English) ⓘ
Narrated Suraqa bin Malik (rad): Allah’s Messenger 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].
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 ٍ (124). 2 - ضعيف. رواه البيهقي (1/96).
also referenced under: Book 1, Hadith 124 (In-Book)