Arabic (Original)
وَقَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أَقِيمُوا الصَّفَّ فِي الصَّلَاةِ فَإِنَّ إِقَامَةَ الصَّفِّ مِنْ حُسْنِ الصَّلَاةِ.
English Translation
The Messenger of Allah (peace be upon him) said: 'Straighten the rows in prayer, for straightening the rows is part of the excellence of prayer.'