The Messenger of Allah, peace and blessings be upon him, said: "The imam is appointed so that he may be followed (in prayer); do not oppose him. Thus, when he says «اللہ أکبر» , you should say «اللہ أکبر» ; when he bows (in ruku‘), you should also bow; when he says «سمع اللہ لمن حمده» , you should (in response) say «اللهم ربنا لك الحمد» ; when he prostrates (in sujud), you should also prostrate; and when the imam prays sitting, you should also pray sitting."