Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) narrates this statement of the Prophet (peace and blessings be upon him): "When Satan comes to any one of you and says, 'You have lost your wudu,' then he should say in his mind, 'You are lying,' until a person hears the sound (of passing wind) with his ear or perceives its smell with his nose (he should not perform wudu again until then)."

Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) narrates that the Prophet Muhammad (peace and blessings be upon him) said: "When a person has doubt about his prayer, he should put the doubt aside and base his action on what he is certain of. When he becomes certain that his prayer is complete, he should perform two prostrations of forgetfulness (sajda sahw). If his prayer was complete, then that extra rak'ah will be counted as a voluntary (nafl) prayer and the two prostrations will also be voluntary. And if his prayer was incomplete, then that rak'ah will complete his prayer and the two prostrations will humiliate the devil."

Sayyiduna Abdullah bin Abbas (may Allah be pleased with him) narrates this statement of the Prophet (peace and blessings be upon him): "When a person performs prayer and is unsure whether he has performed three rak‘ahs or four, he should perform one more rak‘ah and before concluding with salam, he should perform two prostrations of forgetfulness. If it was the fourth rak‘ah, then the two prostrations will disgrace Satan, and if it was the fifth rak‘ah, then the two prostrations will make it even." (Imam Ibn Hibban, may Allah have mercy on him, says:) The narrator named Darawardi made an error in its chain. He said that it is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with him), whereas this narration is actually reported from Sayyiduna Abu Sa‘id Khudri (may Allah be pleased with him). The narrator named Sa‘d bin Ibrahim, since he often narrated hadiths from his memory, it is possible that this was his error.

Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) narrates that the Prophet (peace and blessings of Allah be upon him) said: "When a person is in doubt and does not know whether he has performed three rak'ahs or four, he should stand up and perform one rak'ah, completing its bowing (ruku') and prostration (sujud). Then, when he is sitting, he should perform two prostrations of forgetfulness (sajda sahw). If he had performed five rak'ahs, these two prostrations will make them even, and if he had already performed four rak'ahs, these two prostrations will disgrace Satan." (Imam Ibn Hibban, may Allah have mercy on him, says:) The narration transmitted from Sayyiduna Abdullah ibn Mas'ud (may Allah be pleased with him) and Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) is the narration that caused a learned person to fall into the misunderstanding that making an estimation (taharrī) during prayer and acting upon certainty (yaqīn) are the same thing. Whereas the rulings of both are different. In the narration transmitted from Sayyiduna Abdullah ibn Mas'ud (may Allah be pleased with him), there is the ruling of estimation (taharrī), in which the Prophet (peace and blessings of Allah be upon him) ordered to perform two prostrations of forgetfulness after the salām. Whereas in the narration transmitted from Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him), there is the ruling of acting upon certainty (yaqīn), in which the Prophet (peace and blessings of Allah be upon him) ordered to perform the prostrations of forgetfulness before the salām. So, there is a difference between making an estimation (taharrī) and acting upon certainty (yaqīn). Because acting upon certainty means that if a person is in doubt about his prayer and does not know whether he has performed three rak'ahs or four, when such a situation arises, he will act upon what he is certain of, and that is three rak'ahs. Then he will complete his prayer and perform two prostrations of forgetfulness before the salām. As for estimation (taharrī), its situation is that a person starts the prayer, then his mind becomes occupied with some worldly or religious matter to the extent that he does not know how much of the prayer he has performed. When such a situation arises, he will make an estimation according to what is most likely, and whatever is established for him as a result of this estimation, he will act upon it, then complete his prayer and perform two prostrations of forgetfulness after the salām. In this way, both narrations can be acted upon together.

Sayyiduna Imran bin Husayn (may Allah be pleased with him) narrates: The Prophet (peace and blessings of Allah be upon him) led those people in prayer. He performed the prostration of forgetfulness (sajda sahw) twice, then he recited the tashahhud and concluded the prayer with salam. In narrating this report, the narrator named Ansari is unique; Ibn Sirin has not narrated any other report from Khalid except this hadith, although Khalid is his student.

Sayyiduna Imran bin Husain (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) concluded the ‘Asr prayer after three rak‘ahs. Sayyiduna Khirbaq (may Allah be pleased with him) submitted to him: O Messenger of Allah (peace be upon him)! Did you forget, or has the prayer been shortened? The Prophet (peace be upon him) asked: Is Khirbaq speaking the truth? They replied: Yes! You stood up, performed one rak‘ah, performed the prostration of forgetfulness twice, and then concluded the prayer with salam.

Sayyiduna Imran bin Husain (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) performed two prostrations of forgetfulness while leading them in prayer. He recited the Tashahhud and then concluded the prayer with Salam.

Sayyiduna Imran bin Husain (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) led three rak‘ahs in either Zuhr or ‘Asr prayer (and concluded with salam). This was brought to his attention, so he asked:“Is it so?”The people replied:“Yes.”The Prophet (peace and blessings be upon him) then performed one rak‘ah, recited tashahhud, and concluded with salam. Then he performed two prostrations of forgetfulness (sajda sahw), and then concluded with salam.

Sayyiduna Muawiyah bin Hudaij (may Allah be pleased with him) narrates: I performed the Maghrib prayer behind the Prophet Muhammad (peace and blessings be upon him). The Prophet (peace be upon him) made a mistake and ended the prayer with salam after two rak‘ahs. When the Prophet (peace be upon him) completed the prayer, a man said to him: O Messenger of Allah (peace be upon him)! You made a mistake; you ended the prayer with salam after two rak‘ahs. So the Prophet (peace be upon him) ordered Sayyiduna Bilal (may Allah be pleased with him), who then gave the iqamah for prayer, and the Prophet (peace be upon him) completed that one rak‘ah. I asked the people about the person who had said: O Messenger of Allah (peace be upon him), you made a mistake. I was asked: Do you know him? I replied: No. If I see him, I will recognize him. Then a man passed by me and I said: This is the man. It was said: This is Sayyiduna Talhah bin Ubaidullah (may Allah be pleased with him).

Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) led us in one of the noon prayers. I think it was the Zuhr prayer. He led us in two rak‘ahs (and then gave salam). Then he came and stood by a piece of wood placed in the direction of the qiblah in the mosque, and he placed both his hands on it, one hand over the other. The hasty people left (the mosque), saying,“The prayer has been shortened.”Among those present were Sayyiduna Abu Bakr (may Allah be pleased with him) and Sayyiduna ‘Umar (may Allah be pleased with him), but due to awe, they did not say anything to the Prophet Muhammad (peace and blessings be upon him). The narrator says: Among those present was a man whose hands were perhaps short or perhaps long. He was called Dhu’l-Yadayn. He said,“O Messenger of Allah (peace and blessings be upon him)! Has the prayer been shortened, or have you forgotten?”The Prophet Muhammad (peace and blessings be upon him) said,“The prayer has not been shortened, and I have not forgotten.”He said,“Perhaps you have forgotten.”The Prophet Muhammad (peace and blessings be upon him) asked,“Is Dhu’l-Yadayn speaking the truth?”The people replied,“Yes.”So the Prophet Muhammad (peace and blessings be upon him) led us in two rak‘ahs, then gave salam, then said takbir and performed a prostration like his usual prostrations, or perhaps a little longer, then he raised his head, then said takbir and performed a prostration like his usual prostrations, or perhaps a little longer, then he raised his head and said takbir. The narrator says: I have been informed, this narration is transmitted from Sayyiduna ‘Imran bin Husayn (may Allah be pleased with him), and in it are also these words: Then he gave salam. (Imam Ibn Hibban, may Allah have mercy on him, says:) These three narrations confuse the one who does not have expertise in the science of hadith, and he believes that they contradict each other. In the narration transmitted from Sayyiduna Abu Hurairah (may Allah be pleased with him), it is mentioned that Sayyiduna Dhu’l-Yadayn (may Allah be pleased with him) informed the Prophet Muhammad (peace and blessings be upon him) of this. In the narration transmitted from Sayyiduna ‘Imran bin Husayn (may Allah be pleased with him), it is mentioned that Sayyiduna Khirbaq (may Allah be pleased with him) said this. In the narration transmitted from Sayyiduna Mu‘awiyah bin Khudayj (may Allah be pleased with him), it is mentioned that Sayyiduna Talhah bin ‘Ubaydullah (may Allah be pleased with him) informed the Prophet Muhammad (peace and blessings be upon him) about this. However, there is no contradiction or difference in these narrations. The reason is that in the narration transmitted about Sayyiduna Dhu’l-Yadayn (may Allah be pleased with him), it is mentioned that the Prophet Muhammad (peace and blessings be upon him) gave salam after praying two rak‘ahs of Zuhr or ‘Asr prayer. In the narration transmitted from Sayyiduna ‘Imran bin Husayn (may Allah be pleased with him), it is mentioned that the Prophet Muhammad (peace and blessings be upon him) gave salam after praying three rak‘ahs of Zuhr or ‘Asr prayer. In the narration transmitted from Sayyiduna Mu‘awiyah bin Khudayj (may Allah be pleased with him), it is mentioned that the Prophet Muhammad (peace and blessings be upon him) gave salam after praying two rak‘ahs of Maghrib prayer. So what we have mentioned guides us to the fact that these are three different incidents regarding three different prayers. It is not that all three narrations are about the same prayer.