What one does when he doubts the number of rak'ahs he has prayed and how he performs the prostration for forgetfulness

Question:
May Allah reward you with good, and may He do you good. If a person prays the Fajr prayer and doubts the number of rak'ahs, then adds a rak'ah, but does not perform the prostration for forgetfulness due to forgetfulness or ignorance, and then remembers it after a period of time, does he perform the prostration for forgetfulness? Or if a long time has passed, does he not perform it, and is his prayer valid?

Answer:
If the one praying doubts the number of rak'ahs in Fajr or in any other prayer, if he doubts the number of rak'ahs, he must build upon certainty, which is the lesser number. So if he doubts in Fajr whether he prayed two rak'ahs or one rak'ah, he considers it one rak'ah, stands up, and performs another one. Likewise, if he doubts the number of rak'ahs in the remaining obligatory prayers, he builds upon certainty, which is the lesser number, and completes his prayer. He performs the prostration for forgetfulness after the taslim of the prayer, and if he performs it before the taslim, there is no harm. The matter is broad in this regard. If he forgets the prostration and a period of time has passed, it is dropped from him, and his prayer is valid. If he forgets the prostration and a long time has passed, it is dropped and his prayer is valid, and praise be to Allah. Yes.