Hadith 18400

حَدَّثَنَا حُسَيْنُ بْنُ عَلِيٍّ ، عَنْ زَائِدَةَ ، عَنْ سِمَاكٍ ، عَنِ النُّعْمَانِ بْنِ بَشِيرٍ ، قَالَ : كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يُسَوِّينَا فِي الصُّفُوفِ ، حَتَّى كَأَنَّمَا يُحَاذِي بِنَا الْقِدَاحَ ، فَلَمَّا أَرَادَ أَنْ يُكَبِّرَ ، رَأَى رَجُلًا شَاخِصًا صَدْرُهُ ، فَقَالَ : " لَتُسَوُّنَّ صُفُوفَكُمْ ، أَوْ لَيُخَالِفَنَّ اللَّهُ بَيْنَ وُجُوهِكُمْ " .
It is narrated from Hazrat Nu'man (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) used to straighten the rows (in prayer) as if he were straightening arrows among our rows. Once, when the Noble Prophet (peace and blessings be upon him) intended to say the takbeer, he saw that a man's chest was protruding. The Noble Prophet (peace and blessings be upon him) said: "Keep your rows straight (aligned), otherwise Allah will create discord among you."
Hadith Reference مسند احمد / أول مسند الكوفيين / 18400
Hadith Grading حکم دارالسلام: إسناده صحيح، خ: 717، م: 436