The Prophet (ﷺ) fell from a horse onto his right side, and they entered upon him to visit him. The time for prayer came, and when he had finished praying he said: "The Imam is appointed to be followed, so when he bows, then bow, and when he stands up, then stand up, and when he says: 'Sami' Allahu liman hamidah (Allah hears the one who praises Him)' then say: 'Rabbana wa lakal-hamd (Our Lord, and to You be the praise).'"
Reference: Sunan an-Nasa'i 1061 In-book : Book 12, Hadith 33 English translation : Vol. 2, Book 12, Hadith 1062
Help us gift a modern, ad-free Islamic application for the Muslim Ummah. Your donation will be recorded as Sadaqah Jariyah in your book of deeds, In Sha Allah.