question #3 Sahih al-Bukhari 475, Book 8, Hadith 123 : What does the behavior of the Prophet in the mosque indicate about the etiquette of resting in such a place?

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.