Sahih al-Bukhari 811
Narrated Al-Bara' bin 'Azib:
(and he was not a liar) We used to pray behind the Prophet and when he said, "Sami' a-l-lahu Liman hamida", none of us would bend his back (to go for prostration) till the Prophet had placed his, forehead on the ground.
حَدَّثَنَا آدَمُ، حَدَّثَنَا إِسْرَائِيلُ، عَنْ أَبِي إِسْحَاقَ، عَنْ عَبْدِ اللَّهِ بْنِ يَزِيدَ الْخَطْمِيِّ، حَدَّثَنَا الْبَرَاءُ بْنُ عَازِبٍ ـ وَهْوَ غَيْرُ كَذُوبٍ ـ قَالَ كُنَّا نُصَلِّي خَلْفَ النَّبِيِّ ﷺ فَإِذَا قَالَ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ. لَمْ يَحْنِ أَحَدٌ مِنَّا ظَهْرَهُ حَتَّى يَضَعَ النَّبِيُّ ﷺ جَبْهَتَهُ عَلَى الأَرْضِ.
Classification
Sahih (Authentic)
References
Sahih al-Bukhari 811
Sahih al-Bukhari Vol. 1, Book of Characteristics of Prayer, Hadith 775