حَدَّثَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، وَابْنُ، خَشْرَمٍ قَالاَ أَخْبَرَنَا عِيسَى بْنُ يُونُسَ، حَدَّثَنَا الأَعْمَشُ، عَنْ أَبِي صَالِحٍ، عَنْ أَبِي هُرَيْرَةَ، قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يُعَلِّمُنَا يَقُولُ
" لاَ تُبَادِرُوا الإِمَامَ إِذَا كَبَّرَ فَكَبِّرُوا وَإِذَا قَالَ وَلاَ الضَّالِّينَ . فَقُولُوا آمِينَ . وَإِذَا رَكَعَ فَارْكَعُوا وَإِذَا قَالَ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ . فَقُولُوا اللَّهُمَّ رَبَّنَا لَكَ الْحَمْدُ " .
The Messenger of Allah (ﷺ) while teaching us (the principles of faith), said: Do not try to go ahead of the Imam, recite takbir when he recites it, and when he says: "Nor of those who err" you should say Amin, bow down when he bows down, and when he says: "Allah listens to him who praises Him" say: "O Allah, our Lord, to Thee be the praise".
Source: Sahih Muslim — repository translation · Imam Muslim ibn al-Hajjaj al-Naysaburi — authenticity/grade metadata requires independent source review · Sunnah.comAudio not available for the selected reciter.
Source: Sahih Muslim — repository arabic · Imam Muslim ibn al-Hajjaj al-Naysaburi · Sunnah.com