Literally, Sahv means 'to forget. ' If an act of omission or commission takes place in the prayer due to forgetfulness, two sajdahs, called sajdah sahv have to be performed in the final sitting (Qa'dah) to compensate for the mistake.

The Prescribed Way

After completing Tashahhud in the final sitting position, one turns one's face only to the right with salutation and then saying takbir, performs two sajdahs, one after the other, peacefully. After the second sajdah, one has to repeat Tashahhud, Salat etc., and complete the prayer in the usual way.

Cases in which Sajdah Sahv is Obligatory

1. Omitting a Wajib article of prayer, e.g. the recitation of al Fateha, or a surah after al Fateha etc.

2. Undue delay in the performance of a Wajib or Fard article, e.g. in reciting an additional surah after al Fateha, in bending down for ruku, or in going down for sajdah or changing the sequence of various essential articles, etc.

3. Repeating or overdoing something, e.g. performing ruku twice.

4. Reciting the Qur'an audibly when it should be recited inaudibly, and vice versa, by the Imam.

Regulations Concerning Sajdah Sahv

1. If a Fard part of the prayer is ignored or missed either intentionally or unintentionally, or a Wajib part is missed intentionally, the prayer will be rendered void and no sajdah sahv will set it right and thus it will have to be offered afresh.

2. Two sajdahs of sajdah sahv have to be performed only once in the final sitting position for any number of Wajib articles missed forgetfully during the prayer.

3. If a person recites Tashahhud forgetfully before al Fateha during the standing position, he need not perform sajdah sahv. For the glorification of Allah is allowed before al Fateha and Tashahhud contains a glorification of Allah. If however, Tashahhud is recited after the additional surah in the first rak'ah or before or after the additional surah, in the second rak'ah, sajdah sahv will have to be performed.

4. Forgetting to stand in Qaumah (after ruku), or to sit in Jalsah (between two sajdahs), entails sajdah sahv.

5. If a person forgets to observe the first sitting (Qa'dah) and stands up fully, he should not resume the sitting position upon remembering the mistake, but should complete the prayer and perform sajdah sahv in the final sitting position. If however, he realizes his mistake before standing up fully, he should sit down and need not perform sajdah sahv.

6. If a person forgets to observe the final sitting position in a Fard prayer containing two or four rak'ahs and stands up, he should sit down if he realizes the mistake before performing the sajdah and carry out sajdah sahv to complete the prayer as usual. If, however, he realizes his mistake after performing the sajdah, he should not sit, but should instead offer another rak'ah to complete four or six rak'ahs and need not perform sajdah sahv. For this prayer will be regarded as Nafl, and the Fard prayer will have to be offered afresh. If this happens in the Maghrib prayer, he should add the fourth rak'ah and then observe the final sitting, for according to a Tradition, the Nafl prayer consists of pairs of rak'ahs. ('Ilm-ul-Fiqh, Vol. II, p. 118) .

7. If a person forgets to recite al Fateha, or the Qunut, or Tashahhud, or the additional takbirs in the Eid prayers, sajdah sahv becomes necessary.

8. If the Imam recites the Qur'an inaudibly in the Maghrib, Isha and Fajr prayers by mistake, or inaudibly in the Zuhr and Isha prayers by mistake, he has to perform sajdah sahv.

9. If the Imam omits or ignores an essential article (Wajib) of the prayer, the follower also has to perform sajdah sahv with the Imam, however, if the follower omits at essential article, neither of them has to perform sajdah sahv.

10. If a person omits to recite an additional surah after al Fateha, or recites an additional surah before al Fateha, he should recite another surah (after al Fateha) and must perform sajdah sahv in the final sitting position.

11. If a person omits to recite an additional surah in one or both of the first rak'ahs of the Fard prayer, he may recite an additional surah in one or both of the last rak'ahs as the case may be, and perform sajdah sahv at the end.

12. If a person omits to recite an additional surah in any rak'ah of the Sunnat or Nafl prayer, he must perform sajdah sahv.

13. If in the final sitting of a Fard prayer of four rak'ahs, a person has completed Tashahhud and then has a doubt that this is the first sitting, he should stand up for the fifth rak'ah. Now if before performing the sajdah, he realizes his mistake, he should resume the sitting position and complete his prayer with sajdah sahv. But if he has performed the sajdah of the fifth rak'ah, he should add the sixth rak'ah as well, and complete the prayer with sajdah sahv. The first four rak'ahs will be regarded as the Fard prayer and the last two as Nafl.

14. If the Imam or an individual omits to recite al Fateha, in one or both of the last two rak'ahs of a Fard prayer of four rak'ahs, he need not carry out sajdah sahv, but if he omits to recite al Fateha in any of the Sunnat or Nafl rak'ahs, he will have to perform sajdah sahv because it is essential to recite al Fateha in the first two rak'ahs of a Fard prayer but in all the rak'ahs of the Sunnat and Nafl prayers.

15. If a person carries out two rukus or three sajdahs, in the same rak'ah or recites al Fateha twice, he will have to perform sajdah sahv.

16. If a person begins to recite Salat afterTashahhud in the first sitting, and has recited as much as:

or has sat quiet for so long, he will have to carry out sajdah sahv.

17. If a Masbuq (a follower who has joined late) commits a mistake while he is completing his prayer independently, he has to perform sajdah sahv in the final sitting.

18. If a person pronounces salutation after performing the first two rak'ahs of the Zuhr or Asr Fard prayer, on the presumption that he has completed for rak'ahs and realizes his mistake after the salutation, he should stand up to complete the four rak'ahs and carry out sajdah sahv in the final sitting.

19. If a person develops a doubt during his prayer as to whether he has performed three rak'ahs or four, and he does not have such a doubt normally, he should repeat the whole prayer. But if he generally has such doubts, he should take into account the lesser number of rak'ahs (i.e. three) and complete his prayer with sajdah sahv.

20. If a person omits any Sunnat or Mustahabb part in his prayer, he need not perform sajdah sahv e.g. if he omits Thana in the beginning or forgets to recite Tasbih or ruku, or Salat or the supplication after Salat, sajdah sahv is not necessary.

21. If a person has committed a mistake entailing sajdah sahv but completes his prayer without carrying out sajdah sahv, and realizes this after the salutation, he should immediately perform sajdah sahv and repeat Tashahhud, Salat etc. and complete his prayer, provided that he has not yet turned his face away from the direction of the Qibla nor has had any conversation with another person.

22. If a person performs only one sajdah in a rak'ah, he may make it up in a subsequent rak'ah before Tashahhud, in the final sitting, and perform sajdah sahv. If however, he remembers the mistake after Tashahhud, he should perform the missed sajdah immediately and recite Tashahhud, Salat, etc. again and complete the prayer with sajdah sahv as usual.

23. If a person has offered four rak'ahs instead of two rak'ahs during a journey when it is essential to shorten one's prayer, and has observed the first sitting duly, he should carry out sajdah sahv in the final sitting. In this case, his first two rak'ahs will be regarded as Fard and the remaining two as Nafl.