Chapter on the Rulings on Forgetfulness (Ahkam al-Sahw)

From him, by Hammad ibn ‘Isa, said: One of our companions narrated to me from Abu Hamzah al-Thumali: I (Abu Hamza) saw (Imam) Ali ibn al-Husayn عليه السلام, peace be upon them both, praying, and His عليه السلام cloak fell from His عليه السلام shoulders. Imam عليه السلام did not adjust it until He عليه السلام had completed His عليه السلام prayer. I asked Imam عليه السلام about that, and Imam عليه السلام said: "Woe to you! Do you know before whom I was standing? Indeed, a servant’s prayer is not accepted from him except that part of it in which he was fully attentive." I (Abu Hamza) asked: “May I be your ransom! Then we are doomed.” Imam عليه السلام said: "No, indeed Allah سبحانه وتعالى, the Exalted, completes that with the supererogatory prayers."