Mu'adh bin Jabal narrated that :the Messenger of Allah said: "When one of you comes to the Salat and (finds) the Imam is in a position, then do as the Imam is doing"
SahihSahihDaifBook 6 · Hadith 48
جامع الترمذي
Mu'adh bin Jabal narrated that :the Messenger of Allah said: "When one of you comes to the Salat and (finds) the Imam is in a position, then do as the Imam is doing"