´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.'"
Hadith ReferenceSunan an-Nasa'i / The Book of the Commencement of the Prayer / Hadith: 923
Hadith Gradingالألبانی:حسن صحيح | زبیر علی زئی:صحيح