Sunan an-Nasa'i, Volume 1, Book 10, Hadith 808 (DarusSalam) ⓘ

It was narrated that Abu Mas'ud Al-Ansiri said: "The Messenger of Allah used to gently pat our shoulders (to make sure the row was straight) at the time of prayer, and he-would say:'Keep (the rows) straight; do not differ from one another lest your hearts would be afflicted with discord. Let those who are mature and wise stand closest to me, then those who are next to them, then those who are next to them."' Abu Mas'ud said: Today, there is much disharmony among you.,Abu 'Abdur-Rabin (An-Nasai)said: (One of the narrators) Abu Ma'mar's name is 'Abdullah bin Sakhbarah.

أَخْبَرَنَا هَنَّادُ بْنُ السَّرِيِّ، عَنْ أَبِي مُعَاوِيَةَ، عَنِ الأَعْمَشِ، عَنْ عُمَارَةَ بْنِ عُمَيْرٍ، عَنْ أَبِي مَعْمَرٍ، عَنْ أَبِي مَسْعُودٍ، قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَمْسَحُ مَنَاكِبَنَا فِي الصَّلاَةِ وَيَقُولُ ‏ "‏ لاَ تَخْتَلِفُوا فَتَخْتَلِفَ قُلُوبُكُمْ لِيَلِيَنِّي مِنْكُمْ أُولُو الأَحْلاَمِ وَالنُّهَى ثُمَّ الَّذِينَ يَلُونَهُمْ ثُمَّ الَّذِينَ يَلُونَهُمْ ‏" ‏ ‏.‏ قَالَ أَبُو مَسْعُودٍ فَأَنْتُمُ الْيَوْمَ أَشَدُّ اخْتِلاَفًا ‏.‏ قَالَ أَبُو عَبْدِ الرَّحْمَنِ أَبُو مَعْمَرٍ اسْمُهُ عَبْدُ اللَّهِ بْنُ سَخْبَرَةَ ‏.‏