Sunan an-Nasa'i 821
It was narrated that 'Abdul Hamid bin Mahmud said:
"We were with Anas and we prayed with 
one of the Amirs. They pushed us until we stood and prayed between two rows, and Anas started moving backward and said: 'We used to avoid this at the time of the Messenger of Allah (ﷺ)."
أَخْبَرَنَا عَمْرُو بْنُ مَنْصُورٍ، قَالَ حَدَّثَنَا أَبُو نُعَيْمٍ، عَنْ سُفْيَانَ، عَنْ يَحْيَى بْنِ هَانِئٍ، عَنْ عَبْدِ الْحَمِيدِ بْنِ مَحْمُودٍ، قَالَ كُنَّا مَعَ أَنَسٍ فَصَلَّيْنَا مَعَ أَمِيرٍ مِنَ الأُمَرَاءِ فَدَفَعُونَا حَتَّى قُمْنَا وَصَلَّيْنَا بَيْنَ السَّارِيَتَيْنِ فَجَعَلَ أَنَسٌ يَتَأَخَّرُ وَقَالَ قَدْ كُنَّا نَتَّقِي هَذَا عَلَى عَهْدِ رَسُولِ اللَّهِ صلى الله عليه وسلم ‏.‏