The virtue of prayer in congregation, and clarifying the stern warning against staying away from it, and that it is fard kifayah
وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا أَبُو أُسَامَةَ، وَابْنُ، نُمَيْرٍ ح قَالَ وَحَدَّثَنَا ابْنُ نُمَيْرٍ، حَدَّثَنَا أَبِي قَالاَ، حَدَّثَنَا عُبَيْدُ اللَّهِ، بِهَذَا الإِسْنَادِ . قَالَ ابْنُ نُمَيْرٍ عَنْ أَبِيهِ، " بِضْعًا وَعِشْرِينَ " . وَقَالَ أَبُو بَكْرٍ فِي رِوَايَتِهِ " سَبْعًا وَعِشْرِينَ دَرَجَةً " .
Ibn Numair reported it on the authority of his father (a preference of) more than twenty (degrees) and Abu Bakr in his narration (has narrated it) twenty- seven degrees.