The virtue of prayer in congregation, and clarifying the stern warning against staying away from it, and that it is fard kifayah
وَحَدَّثَنَاهُ ابْنُ رَافِعٍ، أَخْبَرَنَا ابْنُ أَبِي فُدَيْكٍ، أَخْبَرَنَا الضَّحَّاكُ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " بِضْعًا وَعِشْرِينَ " .
Ibn 'Umar reported from the Messenger of Allah (ﷺ) as some and twenty (degrees).