Sahih Muslim , Book 24, Hadith 5239 (USC-MSA) ⓘ
'Abbad b. Tamim reported from his uncle that he saw Allah's Messenger lying in the mosque and placing his one foot upon the other.
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 .
also referenced under: Book 37, Hadith 119 (In-Book) & Hadith 2100 (Reference)