Ibn Hibban

Sayyiduna Abu Hurairah, may Allah be pleased with him, narrates this statement of the Prophet Muhammad, peace and blessings be upon him: "The Imam has been appointed so that he may be followed. When he says the takbeer, you should also say the takbeer. When he goes into ruku', you should also go into ruku'. When he raises (his head from ruku'), you should also raise (your heads). When he recites «سَمِعَ اللهُ لِمَنْ حَمِدَهُ», you should recite «اللَّهُمَّ رَبَّنَا لَكَ الْحَمْدُ». When he performs the prayer standing, you should also perform the prayer standing. When he performs the prayer sitting, then all of you should also perform the prayer sitting." (Imam Ibn Hibban, may Allah have mercy on him, says:) The Prophet Muhammad, peace and blessings be upon him, making the command for the followers firm, that when their Imam is performing the prayer standing, they should perform the prayer standing, and when their Imam is performing the prayer sitting, they should perform the prayer sitting, is the greatest clarification that the Prophet, peace and blessings be upon him, did not mean tashahhud in both commands, rather he meant that standing (qiyam) which is obligatory in the prayer, that a person should perform it in the same manner as the Imam performs it.