1008 - 'Amr ibn 'Uthman narrated to us, saying: Anas ibn 'Iyad narrated to us, from Rabi'ah ibn Abi 'Abd al-Rahman, who said: Muhammad ibn 'Ali came having missed some of the prayer with the imam. When the imam performed the taslim, he did not know how much he had caught, so he gestured to his right, but they did not understand. Then he gestured to the other side, but they did not understand. When he saw that, he said: "How much did I catch?" When they gave him certainty, he based his prayer on what was certain.
Chapter: Regarding one who forgets behind the imam
• I heard Ahmad ibn Hanbal say: "There is no forgetfulness (sujud al-sahw) required for one who is behind the imam, but if a man forgets after the imam, then he must perform the prostration of forgetfulness."
• And I heard Ishaq ibn Ibrahim say: "If a man forgets behind the imam in any part of his prayer, there is no prostration of forgetfulness upon him. They only have a prostration of forgetfulness if the imam forgets. If one behind him forgets, there is no forgetfulness upon him."
• I heard Ishaq say: "If the imam forgets and does not perform the prostration, then those behind him should not prostrate, for the prostration is only upon them if he prostrates."
1009 - Muhammad ibn Yahya narrated to us, saying: 'Abd al-A'la narrated to us, saying: Hisham ibn Hassan narrated to us, that a man prayed behind one of the imams of Basra and he made a mistake, but he did not perform the prostration. He said: "I performed the prostration, then I went to Muhammad ibn Sirin and asked him about it. He said: 'You did well.'"