Sunan Abi Dawud, Hadith 555 ⓘ
‘Uthman b. ‘Affan reported the Messenger of Allah (may peace be him) as saying; if anyone says the night prayer in congregation, he is like one who keeps vigil (in prayer) till midnight; and he who says both the night and dawn prayer in congregation is like one who keeps vigil (in prayer) the whole night.
حَدَّثَنَا أَحْمَدُ بْنُ حَنْبَلٍ، حَدَّثَنَا إِسْحَاقُ بْنُ يُوسُفَ، حَدَّثَنَا سُفْيَانُ، عَنْ أَبِي سَهْلٍ، - يَعْنِي عُثْمَانَ بْنَ حَكِيمٍ - حَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ أَبِي عَمْرَةَ، عَنْ عُثْمَانَ بْنِ عَفَّانَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنْ صَلَّى الْعِشَاءَ فِي جَمَاعَةٍ كَانَ كَقِيَامِ نِصْفِ لَيْلَةٍ وَمَنْ صَلَّى الْعِشَاءَ وَالْفَجْرَ فِي جَمَاعَةٍ كَانَ كَقِيَامِ لَيْلَةٍ " .
also referenced under: Hadith 555 (DarusSalam) & Book 2, Hadith 555 (USC-MSA)