Arabic (Original)
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 (peace be upon him) used to teach us not to precede the imam in bowing and prostrating, and: "When he says Allahu Akbar, say Allahu Akbar. When he prostrates, prostrate. When he says 'not of those who earned anger, nor of those who went astray,' say Ameen, for when it coincides with the words of the angels, whoever is in the mosque will be forgiven. And when he says 'Allah hears the one who praises Him,' say 'Our Lord, to You belongs all praise.'"