Sunan Abi Dawud 21171
In-book no 667حَدَّثَنَا مُسْلِمُ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا أَبَانُ، عَنْ قَتَادَةَ، عَنْ أَنَسِ بْنِ مَالِكٍ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ " رُصُّوا صُفُوفَكُمْ وَقَارِبُوا بَيْنَهَا وَحَاذُوا بِالأَعْنَاقِ فَوَالَّذِي نَفْسِي بِيَدِهِ إِنِّي لأَرَى الشَّيْطَانَ يَدْخُلُ مِنْ خَلَلِ الصَّفِّ كَأَنَّهَا الْحَذَفُ " .
Narrated Anas ibn Malik: The Prophet (ﷺ) said: Stand close together in your rows, bring them near one another, and stand neck to neck, for by Him in Whose hand my soul is, I see the devil coming in through openings in the row just like a small black sheep.