When is the prostration for forgetfulness performed before the closing salam, and when is it performed after the closing salam?

Question:
Peace be upon you. Your Eminence, father, the questioner asks: When is the prostration for forgetfulness performed after the closing salam of the prayer?

Answer:
If the forgetfulness involves an addition in the prayer, meaning if one adds to the prayer, it is recommended that the prostration for forgetfulness be performed after the closing salam. If the prostration is for a deficiency in the prayer, it is recommended that it be performed before the closing salam, because it is a compensation. The compensation is performed before the closing salam. As for permissibility, it is permissible to perform the entire prostration before the closing salam or to perform it entirely after the closing salam. Permissibility applies to both; the distinction is only regarding what is better.