Chapter on Rulings on Forgetfulness (Sahw) in Prayer and What Requires Repeating of Prayer

And what was narrated by Muhammad bin Ahmad bin Yahya, from Ahmad bin Muhammad, from Ibn Sinan, from Abu al-Jarud, who said: I said to Abu Ja‘far عليه السلام, peace be upon him: “When should I perform the two prostrations of forgetfulness (‘sajdatay al-sahw’)?” Imam عليه السلام said: "Before the ‘taslim’, for if you give the ‘taslim’, the sanctity of your prayer has ended."