Chapter on the Manner of Prayer, Explanation of the Fifty-One Rak‘ahs; The Order, Recitation, Tasbih in Bowing and Prostration, Qunut, and What is Obligatory and Recommended Therein

Muhammad ibn Ya‘qub, from Ali ibn Ibrahim, from his father, from Yahya ibn Abd al-Rahman ibn Khaqan, who said: I saw Aba al-Hasan al-Thalith عليه السلام, peace be upon him, perform the prostration of gratitude (‘Sajdat al-Shukr’), and He عليه السلام spread out his forearms and pressed his chest and stomach to the ground. So I asked Him عليه السلام about that, and Imam عليه السلام said: “This is how it should be.”