Prohibition of pronouncing the Takbir before the Imam

 275. Abu Hurairah narrated: The Messenger of Allah salla alayhi wa sallam while teaching us saying, ´´Do not try to be ahead of the Imam, recite Takbir when he recites it; and when he says, ´Wa laddallin´, you should say, ´Amin´, bow down when he bows down; and when he says: ´Sami´ Allahuliman hamida´, say: ´Rabbana lakal-hamd.´´