Section: Additions are of two types: addition of actions and addition of statements. Additions of actions are divided into two categories: First, an addition from the nature of the prayer, such as standing in a place of sitting, sitting in a place of standing, or adding a rak'ah or a pillar. The prayer is invalidated by the intentional commission of this, and one performs the prostration of forgetfulness for it, whether it is small or large, due to the saying of the Prophet (peace and blessings of Allah be upon him): "If a man increases or decreases, let him prostrate twice." Narrated by Muslim (54). The second category is that which is not of the nature of the prayer, such as walking, scratching, or fanning oneself. The prayer is invalidated by a large amount of this, while a small amount is excused, and one does not perform prostration for it, with no difference between intentional and forgetful commission.

The second type is the addition of statements, and it is also divided into two categories: First, that which, if done intentionally, invalidates the prayer, such as the taslim and the speech of humans. If he performs it out of forgetfulness, such as saying the taslim in the wrong place, he prostrates, according to what we mentioned regarding the hadith of Dhu al-Yadayn (55). If he speaks in the prayer out of forgetfulness, does the prayer become invalidated or does he perform the prostration of forgetfulness? There are two narrations.

The second category is that which, if done intentionally, does not invalidate the prayer. It is of two types: First, bringing a recitation or invocation prescribed in the prayer but in the wrong place, such as reciting in the bowing or prostration, saying the tashahhud while standing, sending blessings upon the Prophet (peace and blessings of Allah be upon him) in the first tashahhud, or reciting a surah in the final two rak'ahs of a four-rak'ah prayer or the final rak'ah of Maghrib, and similar acts. If he does this out of forgetfulness, is the prostration of forgetfulness prescribed for him? There are two narrations. One is that no prostration is prescribed for him, because the prayer is not invalidated by doing it intentionally, so the prostration for forgetfulness is not prescribed, just like leaving the sunan actions. The second is that the prostration is prescribed, due to his (peace and blessings of Allah be upon him) saying: "If one of you forgets, let him prostrate twice while he is sitting." Narrated by Muslim (56). If we say that the prostration is prescribed for him, it is recommended but not obligatory, because it is a compensation for something that is not obligatory, so it is not obligatory, like compensating for other sunan acts. Ahmad said: "The forgetfulness for which prostration is mandatory is that which has been narrated from the Prophet (peace and blessings of Allah be upon him)."