Sunan an-Nasa'i 829
It was narrated that Abu Ishaq said:
"I heard 'Abdullah bin Yazid delivering a Khutbah. He said: 'Al-Bara, who was no liar,told us that when they prayed with the Messenger of Allah (ﷺ) would raise his head from bowing and they would remain standing until they saw him prostrate, then they would prostrate."'
أَخْبَرَنَا يَعْقُوبُ بْنُ إِبْرَاهِيمَ، قَالَ حَدَّثَنَا ابْنُ عُلَيَّةَ، قَالَ أَنْبَأَنَا شُعْبَةُ، عَنْ أَبِي إِسْحَاقَ، قَالَ سَمِعْتُ عَبْدَ اللَّهِ بْنَ يَزِيدَ، يَخْطُبُ قَالَ حَدَّثَنَا الْبَرَاءُ، وَكَانَ، غَيْرَ كَذُوبٍ أَنَّهُمْ كَانُوا إِذَا صَلَّوْا مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم فَرَفَعَ رَأْسَهُ مِنَ الرُّكُوعِ قَامُوا قِيَامًا حَتَّى يَرَوْهُ سَاجِدًا ثُمَّ سَجَدُوا ‏.‏