Suppose that someone is praying salat of asr. After the the second rakat, he/she forgets that he has another 2 rakats and he finishes it. After he finishes everything and gets going back to his work, he notices that he only did 2 rakats of the salat.
What must he do in this situation? Pray all the 4 rakats from the beginning? Or pray only the remaining 2 rakats over it? Or is there a different solution in the Sunnah?
Sujood Saho is part of a Hadith by Bukhari. Here is a translation of one hadith:
Aalqama said: Abdullah Ibn Masoud said, “The prophet (SAAW) prayed (and) Ibrahim (Al Nakh’ie) said, ‘I don’t know if (the prophet) added or missed!’ After (the prophet) finished the prayer with tasleem, the companions asked him, ‘O prophet of Allah, was anything new given in Salah?’ The prophet asked why they asked. The companions said, ‘You did something different than was known to us!’ The prophet rolled his feet and faced Qiblah and prayed 2 sujood (prostrations), then made tasleem (salam) again, and when he turned toward us he said, ‘If something new was revealed during Salah I would have told you about it, but I am human like you (and) I do forget like you forget, so if I forget, remind me, and if someone is doubtful about his Salah let him seek what is right and continue his prayer, then make tasleem and pray two sujood.’” Hadith narrated by Bukhari.
As you can see even after finishing Salah you can do the sujood. I am not sure if there is a time limit on this, but it seems unlikely as none is mentioned. There is a number of rules at the bottom of the page that may clarify on some scholarly deductions. There is a number of other Hadiths giving examples: Abu Hurairah/Ibn Buhaina
You did something different than was known to us! --> I wonder what he did differently.
Commented
Jul 1, 2012 at 14:36
According to Jafari Fiqh it depends on if you have dismissed the prayer condition or not. For example if you look your left or right side the prayer condition is dismissed. If you still have not dismissed the condition of prayer you can stand up and continue prayer (as if you have not said the Salam) and after finishing the prayer perform the Sajsa Sahw (سجده سهو sujud of mistake). But if you have dismissed, that prayer is canceled and should be offered again.
Ref:
By Online Answering from Official website of Grand Ayatollah Makarem Shirazi
According to Wikicek if you remember it before salam you should do sujud sahwi before doing salam but if you remember it after the salam so you just do it directly after the salam.
