BLESSING UPON THE FRONT ROWS H 1109 "The Messenger of Allah, praise and peace be upon him, would pass between the rows from one end to the other to straighten chests and shoulders in the line, saying, 'Do not be out of line, or else your hearts will be in dissension.' He would also say, 'Allah and His angels send down blessings upon the front rows.'" R 1109 Abu Daud with a chain up to Bra'a the son of 'Azib who related that the Messenger of Allah, praise and peace be upon him, said this.
1090- وعن البراءِ بن عازِبٍ رضي الله عنهما ، قَالَ : كَانَ رَسُول اللهِ صلى الله عليه وآله وسلم يَتَخَلَّلُ الصَّفَّ مِنْ نَاحِيَةٍ إلى نَاحِيَةٍ ، يَمْسَحُ صُدُورَنَا وَمَنَاكِبَنَا ، وَيَقُولُ : "لا تَخْتَلِفُوا فَتَخْتَلِفَ قُلُوبُكُمْ" وكانَ يَقُولُ : "إنَّ اللهَ وَمَلائِكَتَهُ يُصَلُّونَ عَلَى الصُّفُوفِ الأُوَلِ" رواه أبُو دَاوُدَ بإسناد حسن .