وَعَن بسر بن محجن عَن أَبِيه أَنَّهُ كَانَ فِي مَجْلِسٍ مَعَ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَأُذِّنَ بِالصَّلَاةِ فَقَامَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَصَلَّى وَرَجَعَ وَمِحْجَنٌ فِي مَجْلِسِهِ فَقَالَ لَهُ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «مَا مَنَعَكَ أَنْ تُصَلِّيَ مَعَ النَّاسِ؟ أَلَسْتَ بِرَجُلٍ مُسْلِمٍ؟» فَقَالَ: بَلَى يَا رَسُولَ اللَّهِ وَلَكِنِّي كُنْتُ قَدْ صَلَّيْتُ فِي أَهْلِي فَقَالَ لَهُ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «إِذَا جِئْتَ الْمَسْجِدَ وَكُنْتَ قَدْ صَلَّيْتَ فَأُقِيمَتِ الصَّلَاةُ فَصَلِّ مَعَ النَّاسِ وَإِنْ كُنْتَ قَدْ صَلَّيْتَ» . رَوَاهُ مَالك وَالنَّسَائِيّ

A man of Asad b. Khuzaima said he put this question to Abu Ayyub al-Ansari

I* pray at home and then go to the mosque and the time to begin the prayer comes, so I pray along with the congregation, but I feel some uneasiness about that. Abu Ayyub replied, “We asked the Prophet about that and he said that such a person gets a portion of the reward for corporate prayer.” * The Arabic has “One of us prays . . . then goes . . .” After that the first person singular is used. While such a construction is quite usual in 'Arabic, it makes impossible English, so I have used the first person all through.Malik and Abu Dawud transmitted it.