When should the prostration of forgetfulness (sujud al-sahw) be performed—before the salām or after it—in the case of someone who prayed one unit (rakʿah) then recited the tashahhud, and during the tashahhud remembered the second unit (rakʿah) and then performed it? And what if he pronounced the salām after the first tashahhud out of forgetfulness and then performed the second unit (rakʿah)?

Scholars have differed on the placement of the prostration of forgetfulness (sujood as-sahw). Some said it is entirely before the salutation (Imam Shafi'i), while others said it is entirely after the salutation (Imam Abu Hanifa). Still others differentiated, saying that if it was due to a deficiency, its place is before the salutation, and if it was due to an addition, its place is after the salutation (Imam Malik). The madhhab (definition) of Ahmad is that it is before the salutation, except for what is explicitly stated in the texts to be after the salutation, such as one who gives the salutation due to a deficiency in his prayer. In this case, the forgetfulness was due to an additional sitting and tashahhud (definition), so its prostration would be after the salutation, based on the hadith (definition) of Dhul-Yadain. There is flexibility in this matter, but it is preferable for one who gives the salutation before completing his prayer to prostrate after the salutation.