(Imām Bukhārī narrates): Musaddad narrated to us, he said: Yahyā ibn Sa'īd narrated to us, from Sufyān, he said: Abū Ishāq narrated to me, he said: 'Abdullāh ibn Yazīd narrated to me, he said: Al-Barā', may Allāh be pleased with him, narrated to me, and he was not a liar, he narrated that:
when the Messenger of Allāh ﷺ said "Sami'a Allāhu liman hamidah", none of us would bend his back until the Prophet ﷺ had performed sajdah, then after that we would perform sajdah.
Imām Bukhārī said: This hadith has been narrated to us by Abū Nu'aim, from Sufyān, from Abī Ishāq, similar to this hadith.
حَدَّثَنَا مُسَدَّدٌ، قَالَ حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، عَنْ سُفْيَانَ، قَالَ حَدَّثَنِي أَبُو إِسْحَاقَ، قَالَ حَدَّثَنِي عَبْدُ اللَّهِ بْنُ يَزِيدَ، قَالَ حَدَّثَنِي الْبَرَاءُ ـ وَهْوَ غَيْرُ كَذُوبٍ ـ قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم إِذَا قَالَ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ. لَمْ يَحْنِ أَحَدٌ مِنَّا ظَهْرَهُ حَتَّى يَقَعَ النَّبِيُّ صلى الله عليه وسلم سَاجِدًا، ثُمَّ نَقَعُ سُجُودًا بَعْدَهُ.
Reference: Sahih Al Bukhari 690