Chapter: The Prostration of Forgetfulness

It is prescribed to correct an excess, a deficiency, or a doubt—not a deliberate act—in both obligatory and voluntary prayers. Thus, whenever a worshipper intentionally adds an action that belongs to the prayer itself—standing, sitting1, bowing, or prostration—the prayer becomes invalid; if he adds it inadvertently, he makes the prostration of forgetfulness. If he adds an extra rakʿah and only realizes after he has finished it, he must prostrate. Should he notice while still in that rakʿah, he is to sit down immediately, recite the tashahhud if he has not yet done so, then perform the prostration and end with the salutation.