Full Sharh — Sunan an-Nasa'i 921
أَخْبَرَنَا الْجَارُودُ بْنُ مُعَاذٍ التِّرْمِذِيُّ، قَالَ حَدَّثَنَا أَبُو خَالِدٍ الأَحْمَرُ، عَنْ مُحَمَّدِ بْنِ عَجْلاَنَ، عَنْ زَيْدِ بْنِ أَسْلَمَ، عَنْ أَبِي صَالِحٍ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِنَّمَا جُعِلَ الإِمَامُ لِيُؤْتَمَّ بِهِ فَإِذَا كَبَّرَ فَكَبِّرُوا وَإِذَا قَرَأَ فَأَنْصِتُوا وَإِذَا قَالَ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ فَقُولُوا اللَّهُمَّ رَبَّنَا لَكَ الْحَمْدُ " .
English Translation
It was narrated that Abu Hurairah said:"The Messenger of Allah (ﷺ) said: 'The Imam is appointed to be followed, so when he says the takbir, say the takbir, and when he recites, be silent, and when he says: "Sami' Allahu liman hamidah (Allah hears those who praise Him)," say: "Allahumma rabbana lakal-hamd (Our Lord, to You be praise)
Source
Sunan an-Nasa'i(سنن النسائي)
The Book of the Commencement of the Prayer
Hadith Number
921
Grade
Hasan Sahih