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

From him, from al-Barqi from Ja’far ibn al-Muthanna al-Khatib from Ishaq ibn Ammar who said: Abu Abdillah عليه السلام, peace be upon him, said to me: “O Ishaq, do you pray with them (the opponents) in the mosque?” I said: “Yes.” Imam عليه السلام said: “Pray with them, for the one who prays with them in the first row is like one who draws his sword in the way of Allah سبحانه وتعالى.” (meaning to have Shia presence in communal religious spaces is a form of jihad)