If one gives the salām before completing the prayer intentionally, the prayer is rendered invalid; if he does so out of forgetfulness and remembers shortly thereafter, he should finish the prayer and perform the prostration of forgetfulness.

If at that point (1)—or in the midst of the prayer—he speaks, laughs out loud (2), blows, or clears his throat without need, and two distinct letters are audible, the prayer is invalid.

Section

If someone omits a pillar (3) and remembers only after beginning the recitation of the next rakʿah, the rakʿah whose pillar was omitted is nullified. If he recalls before starting that recitation, he must return, perform the omitted act along with everything that follows it. Should he remember after the final salām (4), it is as though he had left out an entire rakʿah.

If he forgets the first tashahhud, he must go back to it before he is fully upright; returning after he has straightened is merely disliked. Once he has begun the recitation, going back becomes unlawful and would invalidate the prayer.

He may return to pronounce the tasbīḥ of bowing or prostration before rising upright, but not afterward, and in every such case he must perform the prostration of forgetfulness.

Whoever is uncertain about a pillar or about the number of rakʿahs he has prayed should act on the basis of certainty.

No prostration is made for a doubt (5) concerning an obligatory act that is less than a pillar, and a congregant does not prostrate unless following his imam. A late-comer, however, performs the prostration of forgetfulness for his own errors.

The prostration of forgetfulness is obligatory for any matter whose deliberate commission would nullify the prayer.

Its proper place is before the salām, as a recommended practice, except when one has given the salām before completing the prayer—in that case it is performed afterward.