حَدَّثَنَا حَفْصُ بْنُ عُمَرَ، حَدَّثَنَا شُعْبَةُ، عَنْ أَبِي إِسْحَاقَ، عَنْ عَبْدِ اللَّهِ بْنِ أَبِي بَصِيرٍ، عَنْ أُبَىِّ بْنِ كَعْبٍ، قَالَ صَلَّى بِنَا رَسُولُ اللَّهِ صلى الله عليه وسلم يَوْمًا الصُّبْحَ فَقَالَ ‏"‏ أَشَاهِدٌ فُلاَنٌ ‏"‏ ‏.‏ قَالُوا لاَ ‏.‏ قَالَ ‏"‏ أَشَاهِدٌ فُلاَنٌ ‏"‏ ‏.‏ قَالُوا لاَ ‏.‏ قَالَ ‏"‏إِنَّ هَاتَيْنِ الصَّلاَتَيْنِ أَثْقَلُ الصَّلَوَاتِ عَلَى الْمُنَافِقِينَ وَلَوْ تَعْلَمُونَ مَا فِيهِمَا لأَتَيْتُمُوهُمَا وَلَوْ حَبْوًا عَلَى الرُّكَبِ وَإِنَّ الصَّفَّ الأَوَّلَ عَلَى مِثْلِ صَفِّ الْمَلاَئِكَةِ وَلَوْ عَلِمْتُمْ مَا فَضِيلَتُهُ لاَبْتَدَرْتُمُوهُ وَإِنَّ صَلاَةَ الرَّجُلِ مَعَ الرَّجُلِ أَزْكَى مِنْ صَلاَتِهِ وَحْدَهُ وَصَلاَتُهُ مَعَ الرَّجُلَيْنِ أَزْكَى مِنْ صَلاَتِهِ مَعَ الرَّجُلِ وَمَا كَثُرَ فَهُوَ أَحَبُّ إِلَى اللَّهِ تَعَالَى ‏"

Narrated Ubayy ibn Ka'b

The Messenger of Allah (ﷺ) led us in the dawn prayer one day, then said: "Is so-and-so present?" They said: "No." He said: "Is so-and-so present?" They said: "No." Then he said: "Verily, these two prayers are the heaviest prayers upon the hypocrites. If you knew what is in them, you would surely come to them even if you had to crawl on your knees. Verily, the first row is like the row of the angels. If you knew its excellence, you would race to it. Verily, a man's prayer with another man is purer than his prayer alone, and his prayer with two men is purer than his prayer with one man. And the more there are, the more beloved it is to Allah, the Almighty."