‘Abd Allah (b. Mas’ud) said; The Messenger of Allah (ﷺ) led us in five rak’ahs of prayer. When he turned away (i,e, finished his prayer), the people whispered among themselves. He asked; what is the matter with you ? They said : Messenger of Allah, has (the number of the rak’ahs of) the prayer been increased ? he said : No. they said; you have offered five rak’ahs of prayer. He then turned away and performed two prostrations, and afterwards gave the salutation. He then said : I am only a human being, I forget, as you forget.

Narrated Mu'awiyah ibn Khudayj: One day the Messenger of Allah (ﷺ) prayed and gave the salutation while a rak'ah of the prayer remained to be offered. A man went to him and said: You forgot to offer one rak'ah of prayer. Then he returned and entered the mosque and ordered Bilal (to utter the Iqamah). He uttered the Iqamah for prayer. He then led the people in one rak'ah of prayer. I stated it to the people. They asked me: Do you know who he was? I said: No, but I can recognise him if I see him. Then the man passed by me, I said: It is he. The people said: This is Talhah ibn Ubaydullah.

‘Ata’ b. Yasar said that Abu Sa’id al-Khudri reported the Messenger of Allah (ﷺ) as saying: when one of you is in doubt about his prayer (i.e, how much he has prayed), he should throw away his doubt and base his prayer on what he is sure of. When he is sure about the completion of his prayer, he should make two prostrations (at the end of the prayer). If the prayer is complete, the additional rak’ah and the two prostrations will be supererogatory prayer. If the prayer is incomplete, the additional rak’ahs will compensate it, and the two prostrations will be a disgrace for the devil.

Narrated Abdullah ibn Abbas: The Prophet (ﷺ) named the two prostrations of forgetfulness disgraceful for the devil.

Narrated Ata' ibn Yasar: The Prophet (ﷺ) said: When one of you is in doubt about his prayer, and does not know how much he has prayed, three or four rak'ahs, he should pray one (additional) rak'ah and make two prostrations while sitting before giving the salutation. If the (additional) rak'ah which he prayed is the fifth one, he will make it an even number by these two prostrations. If it is the fourth one, the two prostrations will be a disgrace for the devil.

Zaid b. Aslam reported on the authority of the chain of Malik: The Prophet (ﷺ) said: If one of you is in doubt about his prayer, and if he is sure that he prayed three rak'ah, he should stand and complete one rak'ah along with its prostrations. Then he should sit and recite the tashahhud. When he finishes the prayer, and there remains nothing except salutation, he should make two prostrations while he is sitting and afterwards should give the salutation. The narrator then narrated the tradition similar to that of Malik. Abu Dawud said: Similarly, this tradition has been narrated by Ibn Wahb from Malik, Hafs b. Maisarah, Dawud b. Qais and Hisham b. Sa'd. But Hisham projected it to Abu Sa'id al-Khudri.

AbuUbaydah reported, on the authority of his father Abdullah (ibn Mas'ud), the Messenger of Allah (ﷺ) as saying: When you offer the prayer, and you are in doubt about the number of rak'ahs whether offered three or four, and you have prayed four rak'ahs in all probability in your opinion, you should recite tashahhud and make two prostrations while you are sitting before giving the salutation. afterwards you should recite the tashahhud and give the salutation again. Abu Dawud said: This tradition has been narrated by 'Abd al-Wahid from Khusaif, but he did not report it as a statement of the Prophet (ﷺ). The version of 'Abd al-Wahid has been corroborated by Sufyan, Sharik, and Isra'il. They differed amongst themselves about the text of the tradition and they did not narrate it with the continuous chain up to the Prophet (ﷺ).

Narrated AbuSa'id al-Khudri: The Prophet (ﷺ) said: When one of you prays, and he does not know whether he prayed more or less rak'ahs (than those prescribed by the Shari'ah), he should perform two prostrations while he is sitting. If the devil comes to him, and tells him (suggests him): "You have been defiled," he should say: "You have told a lie," except that he feels smell with his nose, or sound with his ears (then his ablution will break). These are the wording; of the tradition reported by Aban. Abu Dawud said: Ma'mar and 'Abi b. al-Mubarak mentioned the name "Iyad b. Hilal and al-Awza'i mentioned the name of Iyad b. Abi Zuhair.

Abu Hurairah reported the Messenger of Allah (ﷺ) as saying; When one of you stands up to pray, the devil comes to him and confuses him so that he does not know how much he has prayed. If any of you has such an experience, he should perform two prostrations while he is sitting. Abu Dawud said; This tradition has been narrated in a similar manner by Ibn ‘Uyainab, Ma’mar and al-Laith.

This tradition has also been transmitted by Muhammad b. Muslim through a different chain of narrators. This version adds; “While he is sitting before he gives the salutation.”

This traditions has also been narrated by Muhammad b. Muslim al-Zuhr through a different chain of transmitters and to the same effect. This version adds; He should perform two prostrations before giving the salutation.

Narrated Abdullah ibn Ja'far: The Prophet (ﷺ) said: Anyone who is in doubt in his prayer should make two prostrations after giving the salutation.

Narrated Abdullah ibn Buhaynah: The Messenger of Allah (ﷺ) led us in prayer praying two rak'ahs. When he stood up and did not sit (at the end of two rak'ahs) the people stood up along with him. When he finished the prayer and we expect him to give the salutation, he said: "Allah is most great." While sitting and made two prostrations before giving the salutation. Then he gave it.

This tradition (mentioned above) has also been transmitted by al-Zuhri through a different chain of narrators to the same effect. This version adds: Some of us recited the Tashahhud while they were standing. Abu Dawud said: Ibn-Zubair made two prostrations before giving the salutation in a similar way when he stood up at the end of two rak’ahs. This is the opinion of al-Zuhrl.

Narrated Al-Mughirah ibn Shu'bah: The Prophet (ﷺ) said: When an imam stands up at the end of two rak'ahs , if he remembers before standing straight up, he should sit down, but if he stands straight up, he must not sit down, but perform the two prostrations of forgetfulness. Abu Dawud said: I have not narrated in this book of mine any hadith from Jabir Al-Ju'fi (one of the narrators) except this one.

Narrated Al-Mughirah ibn Shu'bah: Ziyad ibn Ilaqah said: Al-Mughirah ibn Shu'bah led us in prayer and he stood up at the end of two rak'ahs. We said: Glory be to Allah; he also said: Glory be to Allah, and he proceeded. When he finished the prayer and gave the salutation, he made two prostrations of forgetfulness. When he turned (to us) he said: I saw the Messenger of Allah (ﷺ) doing so as I did. Abu Dawud said: Ibn Abi Laila narrated this tradition in a similar manner from al-Shaibi from al-Mughirah b. Shu'bah. Abu 'Umais narrated it from Thabit b. 'Ubaid saying: "Al-Mughirah b. Shu'bah led us in prayer, like the tradition reported by Ziyad b. 'Illaqah. Abu Dawud said: Abu 'Umais is the brother of al-Mas'udi. And Sa'd b. Abi Waqqas did the same as done by al-Mughirah, 'Imran b. Husain, Dahhak b. Qais and Mu'awiyah b. Abi Sufyan. Ibn 'Abbas and 'Umar b. 'Abd al-'Aziz issued legel verdict to the same effect. Abu Dawud said: This applies to a person who stands up at the end of two rak'ahs and males prostration after giving the salutation.

Narrated Thawban: The Prophet (ﷺ) said: For each forgetfulness there are two prostrations after giving the salutation. No one except Amr (ibn Uthman) mentioned the words "from his father" (in the chain AbdurRahman ibn Jubayr ibn Nufayr from Thawban).

Narrated Imran ibn Husayn: The Prophet (ﷺ) led them in prayer and forgot something, so he made prostrations and uttered the tashahhud, then gave the salutation.

Umm Salamah said; When the Messenger of Allah (ﷺ) gave the salutation, he stayed for a while. By this people thought that women should return earlier than men.

Narrated Hulb (Yazid) at-Ta'i: Hulb prayed along with the Prophet (ﷺ). He used to turn to both his sides (sometimes to the left and sometimes to the right).