Sunan Ibn Majah, Volume 1, Book 4, Hadith 751 (DarusSalam) ⓘ
It was narrated that Ibn 'Umar said: "We used to sleep in the mosque at the time of the Messenger of Allah."
حَدَّثَنَا إِسْحَاقُ بْنُ مَنْصُورٍ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ نُمَيْرٍ، أَنْبَأَنَا عُبَيْدُ اللَّهِ بْنُ عُمَرَ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، قَالَ كُنَّا نَنَامُ فِي الْمَسْجِدِ عَلَى عَهْدِ رَسُولِ اللَّهِ ـ صلى الله عليه وسلم ـ .
also referenced under: Hadith 751 (Reference) & Book 4, Hadith 17 (In-Book)