Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) narrates that the Noble Prophet (peace and blessings be upon him) said: If anyone is uncertain in prayer whether he has prayed three (rak‘ahs) or four, he should stand up and pray one more rak‘ah, so that the doubtful rak‘ah becomes an extra one. Then, before the salam, he should perform two prostrations of forgetfulness (sujud al-sahw). If he has prayed five rak‘ahs, these prostrations will make them even, and if he has prayed only four, they will humiliate Satan.

Sayyiduna Abdullah bin Buhaina (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) led them in prayer, and after two rak‘ahs he stood up (without sitting for tashahhud). We said «سبحان الله» , but he continued the prayer, then performed two (sujood as-sahw) prostrations and ended the prayer with salam. These are the words of Ahmad bin Sa‘eed al-Darimi.

Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) led us in one of the prayers after the sun had declined, either Zuhr or Asr—I think it was Asr. After leading two rak‘ahs, he said salam and ended the prayer. Then, angrily, he moved forward and sat by a date-palm trunk. Those who were quick to leave began saying,“The prayer has been shortened, the prayer has been shortened.”Dhu’l-Yadayn (may Allah be pleased with him) came forward and asked,“O Messenger of Allah! Has the prayer been shortened, or did you forget?”He said,“Is Dhu’l-Yadayn speaking the truth?”The people replied,“Yes!”The narrator says: He (the Prophet) then performed two more rak‘ahs and said salam, then said takbir and prostrated, then said takbir and raised his head, then said takbir and prostrated, then said takbir and raised his head.

Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) led us in prayer, and there was either a deficiency or an addition in it. Ibrahim says: This doubt occurred to Alqamah, or Alqamah narrated it from Abdullah bin Mas'ud. After completing the prayer, the Messenger of Allah (peace and blessings be upon him) turned towards us, so we asked: O Messenger of Allah! Has a new command regarding prayer been revealed? He said: What happened? We informed him, so he folded his legs and, facing the Qiblah, performed two prostrations. Then, turning his blessed face towards us, he said: If a new command regarding prayer had been revealed, I would have informed you, but I am also a human being; I remember as you do, and I forget as you do. When I forget, remind me. Whoever has doubt in his prayer should determine what is more correct, then complete the prayer accordingly, and after saying salam, perform two prostrations.

Sayyiduna Imran bin Husayn (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) led three rak‘ahs of the ‘Asr prayer and then said the salam. He was informed about it, so he led one more rak‘ah, then after saying the salam, he performed two prostrations and then said the salam again.

Ibrahim bin Suwaid (may Allah have mercy on him) says: Alqamah (may Allah have mercy on him) led them in a prayer of five rak‘ahs. The people said: O Abu Shibl! You have added to the prayer. He said: I have not added anything. The people said: You have added. Ibrahim says: I also said from one side of the mosque: Yes! (You have added.) Alqamah (may Allah have mercy on him) said: O Okane! Do you also say the same? So he turned and performed two prostrations. Then he narrated to them from Sayyiduna Abdullah bin Mas‘ud (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) had led them in a prayer of five rak‘ahs, then he performed two prostrations while sitting, then said: I am also a human being; just as you forget, I also forget. By this is meant Ibrahim bin Suwaid al-Nakha‘i, not Ibrahim bin Yazid al-Nakha‘i.

Sayyiduna Imran bin Husayn (may Allah be pleased with him) narrates that the Messenger of Allah (peace and blessings be upon him) led them in prayer. He forgot during the prayer, then the Messenger of Allah (peace and blessings be upon him) performed two prostrations of forgetfulness, then recited the tashahhud and concluded with salam.