Sahih al-Bukhari
Book 8: Prayers (Salat)
كتاب الصلاة
167 hadith in this book
Chapter 85 To lie flat (on the back) in the mosque
باب الاِسْتِلْقَاءِ فِي الْمَسْجِدِ وَمَدِّ الرِّجْلِ
Narrated `Abbad bin Tamim:
that his uncle said, "I saw Allah's Messenger (ﷺ) lying flat (on his back) in the mosque with one leg on the other." Narrated Sa`id bin Al-Musaiyab that `Umar and `Uthman used to do the same.
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ، عَنْ 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. وَعَنِ ابْنِ شِهَابٍ عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ قَالَ كَانَ عُمَرُ وَعُثْمَانُ يَفْعَلاَنِ ذَلِكَ.
Hadith text, translations and grading are courtesy of Sunnah.com.