Hadith #67
Arabic Text
وَبِإِسْنَادِهِ قَالَ كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يُعَلِّمُنَا أَنْ لَا نُبَادِرَ الْإِمَامَ بِالرُّكُوعِ وَالسُّجُودِ وَإِذَا كَبَّرَ فَكَبِّرُوا وَإِذَا سَجَدَ فَاسْجُدُوا وَإِذَا قَالَ { غَيْرِ الْمَغْضُوبِ عَلَيْهِمْ وَلَا الضَّالِّينَ } فَقُولُوا آمِينَ فَإِذَا وَافَقَ كَلَامَ الْمَلَائِكَةِ غُفِرَ لِمَنْ فِي الْمَسْجِدِ وَإِذَا قَالَ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ فَقُولُوا رَبَّنَا لَكَ الْحَمْدُ
English Translation
And with the same chain of narration, he said: the Messenger of Allah ﷺ used to teach us not to precede the imam in bowing and prostration. 'When he says the takbir, say the takbir. When he prostrates, prostrate. When he says {Not of those who earned Your anger, nor of those who went astray}, say Ameen. If it coincides with the speech of the angels, whoever is in the mosque will be forgiven. When he says: Allah hears the one who praises Him, say: Our Lord, to You belongs all praise.'
Quran References
Reference: Musnad Ahmad, Book 21, Hadith 67
Sunnah.com ref: Musnad Ahmad 9305
Islam.wiki ID: IWH-45695