Sahih al-Bukhari 722
Book 10: Call to Prayers (Adhaan) · Hadith 116
Hadith text
Narrated Abu Huraira:The Prophet (ﷺ) said, "The Imam is (appointed) to be followed. So do not differ from him, bow when he bows, and say, "Rabbana-lakal hamd" if he says "Sami`a l-lahu liman hamidah"; and if he prostrates, prostrate (after him), and if he prays sitting, pray sitting all together, and straighten the rows for the prayer, as the straightening of the rows is amongst those things which make your prayer a correct and perfect one. (See Hadith No)
Abu Huraira (رضی اللہ عنہ) se riwayat hai ke Nabi ne farmaya: "Imam ki pairvi ki jaati hai, isliye uske khilaaf mat karo. Jab woh ruku kare, tum bhi karo, aur jab woh 'Sami' Allahu liman hamidah' kahe, tum 'Rabbana lakal-hamd' kaho; jab sajda kare, tum bhi karo; aur agar woh baithkar padhe, sab baithkar padho; aur safein seedhi karo, kyunke safon ka seedha hona namaz ki sehat-o-kamal mein shamil hai."
Sahih al-Bukhari 722 · Book 10, Hadith 116