It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: The Imam is appointed only so that he may be followed, so when he says the takbeer, you also say the takbeer; when he recites (Qur'an), you remain silent; when he says "Sami' Allahu liman hamidah," you say "Rabbana wa lakal hamd"; and when he prays sitting, then all of you also pray sitting.