Chapter on the Rulings of Congregational Prayer (the Minimum Number for Congregational Prayer, the Description of the Imam, Who Is to Be Followed and Who Is Not to Be Followed, Recitation Behind Both of Them, the Rulings of Those Led in Prayer, and Other Such Rulings Related to It)

And from him, from Bunan ibn Muhammad from his father from Ibn al-Mughirah from al-Sakuni from Imam Ja’far عليه السلام, from his father عليه السلام, from Imam Ali عليه السلام, peace be upon him: Imam Ali عليه السلام used to say: “When a man enters the mosque and its people have already prayed, then he should not give the adhan, nor should he give the iqamah, and he should not perform supererogatory prayers until he begins with the obligatory prayer. And he should not leave it (the mosque) for another place until he has prayed in it.”