I prayed the 'Isha' prayer and had a doubt in one of the prostrations, and I forgot to perform the prostration for forgetfulness, so I repeated the 'Isha' prayer. What is the ruling on what I did?

Question:
May Allah reward you with good and do you well. I prayed the 'Isha' prayer and had a doubt that I had prostrated only once in one of the four rak'ahs. I intended to perform the prostration for forgetfulness, but I forgot and did not prostrate. Since I did not remember until after I had stood up for the two rak'ahs of the regular voluntary prayer, I then repeated the 'Isha' prayer. What is the ruling on what I did, and what is the ruling on my second prayer? May Allah reward you with good.

Answer:
If you have a doubt regarding the prostration, it is treated as if you left the prostration. The scholars said that if one has a doubt about leaving a pillar, it is as if he left it.
If you left the prostration and you remember, if the doubt occurred while you were in the prayer, if the doubt occurred while you were in the prayer, then it is obligatory for you to invalidate the rak'ah in which you doubted leaving the prostration, and to perform a rak'ah in its place, and to complete your prayer, and to prostrate twice for forgetfulness. The rak'ah in which the doubt occurred is considered invalid, and you perform a valid rak'ah in its place, and you complete your prayer, and you prostrate twice for forgetfulness. Except if the doubt occurred before you entered the next rak'ah, in which case you go back and perform what you doubted about, then you stand for the next rak'ah and prostrate for forgetfulness. As for if you prayed and no doubt occurred with you, but you only had a doubt after finishing the prayer, then this doubt has no effect, because a doubt after performing the act of worship does not attach to it, and it has no impact. Yes.