It is narrated from Hazrat Abu Hurairah (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: Whoever obeys me has indeed obeyed Allah, and whoever disobeys me has disobeyed Allah. Whoever obeys the leader has obeyed me, and whoever disobeys the leader has disobeyed me. And the leader is like a shield, so when he says the takbeer, you should also say the takbeer; when he bows (in ruku‘), you should also bow; when he says "Sami‘ Allahu liman hamidah," you should say "Rabbana lakal hamd," because whoever’s saying coincides with that of the angels, his sins are forgiven. And when he prays sitting, then all of you should also pray sitting.