Sujud-ul-Sahw.

Sujud-ul-Sahw.

Ruling when in doubt about the number of Rak‘ahs preformed during a Salah.


Q: During a four-Rak‘ah Salah (Prayer consisting of four units)
an Imam was doubtful and did not know whether he had performed three or four Rak‘ahs. When he concluded the Taslim (salutation of peace ending the Prayer), he was informed by the Ma’mums (those praying behind an Imam) that he had only performed three Rak‘ahs.
Should the Imam get up and say the Takbirat-ul- Ihram saying: "Allahu Akbar ?[Allah is the Greatest]" upon starting Prayer) for the fourth Rak‘ah or just get up and recite Al-Fatihah without saying the Takbir?
As for Sujud-ul-Sahw (Prostration of Forgetfulness) , should it be performed before the Taslim or after it?

Answer:-

If the Imam or someone performing a four-Rak‘ah Salah alone is in doubt about the number of Rak‘ahs, and does not know whether they have performed three or four, it is obligatory on them to base their Salah on what they are sure of, which is the lower number.
They should consider that they have performed three Rak‘ahs and perform a fourth. They should then perform the Sujud-ul-Sahw before the Taslim. This was authentically reported by Abu Sa‘id Al-Khudary, who said that the Prophet (peace be upon him) said:-
“If any of you doubts during their Salah and does not know whether they have performed three or four (Rak‘ahs), they should cast aside their doubts and build on what they are sure of. Then they should perform two prostrations before offering Taslim (salutation of peace ending the Prayer).

If the Rak‘ah they have prayed is the fifth, they (the two prostrations) will make their Salah of an even number of Rak‘ahs; and if by praying it they have completed four Rak‘ahs, they (the two prostrations) will be vexing humiliation for Satan.�
(Related by Muslim in his "Sahih [Book of Authentic Hadith]").