Chapter on the Virtue of Mosques and Prayer Within Them, and the Virtue of Congregational Prayer and Its Rulings

Muhammad ibn Ali ibn Mahbub from al-Qasim ibn Urwah from Ubayd ibn Zurarah from Abu Abdillah عليه السلام, peace be upon him, who said: I asked Imam al-Sadiq عليه السلام: “I enter the mosque having already prayed, so I pray with them but I do not count that prayer (as my obligation).” Imam عليه السلام said: “There is no problem. As for me, I pray with them and make it appear to them that I am prostrating, but I do not actually prostrate.”