Ahmad ibn al-Hasan ibn Ali from Amr ibn Saeed from Musaddiq ibn Sadaqah from Ammar who said: I asked Abu Abdillah عليه السلام, peace be upon him, about a man who catches the imam (of prayer) while he is sitting after the two rak‘ahs. Imam عليه السلام said: “He should begin the prayer anew and should not sit with the imam (of prayer) until the imam (of prayer) stands.”