وَعَنْ سُرَاقَةَ بْنِ مَالِكٍ رضى الله عنه
قَالَ: «عَلَّمْنَا رَسُولُ اَللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فِي اَلْخَلَاءِ: «أَنَّ نَقْعُدَ عَلَى اَلْيُسْرَى، وَنَنْصِبَ اَلْيُمْنَى»
The Messenger of Allah (sallallahu alayhi wa sallam) educated us about lavatory (manners) that we should sit on our left foot and keep erect our right foot.
Bulugh al-Maram 124, Book 1, The Book of Purification, Hadith 124. 1 min read