It was narrated that Jabir bin Samurah As-Suwa’i said:
“The Messenger of Allah ﷺ said: ‘Will you not form your rows as the angels form their rows before their Lord?’ We said: ‘How do the angels form their rows before their Lord?’ He said: ‘They complete the first row and they stand close of one another in the line (leaving no gaps between one another).’”

حَدَّثَنَا عَلِيُّ بْنُ مُحَمَّدٍ، حَدَّثَنَا وَكِيعٌ، حَدَّثَنَا الأَعْمَشُ، عَنِ الْمُسَيَّبِ بْنِ رَافِعٍ، عَنْ تَمِيمِ بْنِ طَرَفَةَ، عَنْ جَابِرِ بْنِ سَمُرَةَ السُّوَائِيِّ، قَالَ قَالَ رَسُولُ اللَّهِ ﷺ " أَلاَ تَصُفُّونَ كَمَا تَصُفُّ الْمَلاَئِكَةُ عِنْدَ رَبِّهَا " . قَالَ قُلْنَا وَكَيْفَ تَصُفُّ الْمَلاَئِكَةُ عِنْدَ رَبِّهَا قَالَ " يُتِمُّونَ الصُّفُوفَ الأُوَلَ وَيَتَرَاصُّونَ فِي الصَّفِّ " .