Sunan an-Nasa'i 1243

Al-Hasan ibn Isma‘il ibn Sulayman al-Mujalidi reported to us; he said: al-Fudayl—meaning, Ibn ‘Iyad—reported to us, from Mansur, from Ibrahim, from ‘Alqamah, from ‘Abd Allah, who said: The Messenger of Allah (ﷺ) prayed and did more or less than intended. When he said the taslim, we said: “O Prophet of Allah, has something happened in the prayer?” He said: “What is that?” We told him what he had done. He folded his leg, turned toward the qiblah, and prostrated twice for forgetfulness. Then he turned to face us and said: “If anything had happened in the prayer, I would have informed you.” Then he said: “I am only a human being; I forget just as you forget. So whoever among you is uncertain about something in his prayer, let him determine which course he believes to be correct; then let him say the taslim and prostrate twice for forgetfulness.”