Chapter: The Two Prostrations of Forgetfulness (Sujud al-Sahw)

Imam Ahmad said: Five things are preserved from the Prophet (peace be upon him); he performed the taslim (salutation) after two [rak'ahs] and prostrated, he performed the taslim after three and prostrated, and [he prostrated for] both addition and omission, and he stood up from two [rak'ahs] and did not sit for the [first] tashahhud. Al-Khattabi said: The relied-upon [traditions] among the people of knowledge (120) are these five hadiths (121), meaning the two hadiths of Ibn Mas'ud, and those of Abu Sa'id, Abu Hurayrah, and Ibn Buhaynah.

214 - Issue: Abu al-Qasim said: (And whoever performs the taslim, while something of his prayer remains, let him perform what remains of his prayer, perform the taslim, then prostrate for the two prostrations of forgetfulness, then sit for the tashahhud and perform the taslim, just as it was narrated from Abu Hurayrah and 'Imran ibn Husayn, from the Prophet - peace be upon him - that he did that.)

The entirety of this is that whoever performs the taslim before completing his prayer (1) out of forgetfulness, then realizes it before the passage of a long duration and before the invalidation of his ritual purity (wudu'), he must perform what remains, then sit for the tashahhud and perform the taslim, then prostrate [the two prostrations of forgetfulness] (2), and perform the tashahhud and the taslim. If he does not remember until he has stood up, he must sit down so that he may rise to perform what remains from a sitting position; for this standing is obligatory for the prayer, and he did not perform it with the intention for it, so it was incumbent upon him to perform it with the intention (3). We do not know of any disagreement regarding the permissibility of completing the prayer for one who forgot a rak'ah (4) or more. The basis for this is what Ibn Sirin narrated from Abu Hurayrah, who said: The Messenger of Allah (peace be upon him) led us in one of the two evening prayers - Ibn Sirin said: