The Book of Clothes and Adornment
37/22. Chapter:
The Permissibility Of Lying Down And Placing One Leg On Top Of The Other
Sahih Muslim
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، قَالَ قَرَأْتُ عَلَى مَالِكٍ عَنِ ابْنِ شِهَابٍ، عَنْ عَبَّادِ بْنِ تَمِيمٍ، عَنْ عَمِّهِ، أَنَّهُ رَأَى رَسُولَ اللَّهِ صلى الله عليه وسلم مُسْتَلْقِيًا فِي الْمَسْجِدِ وَاضِعًا إِحْدَى رِجْلَيْهِ عَلَى الأُخْرَى .
'Abbad b. Tamim reported from his uncle that he saw Allah's Messenger (ﷺ) lying in the mosque and placing his one foot upon the other.
Reference : Sahih Muslim 2100aIn-book reference : Book 37, Hadith 119USC-MSA web (English) reference : Book 24, Hadith 5239