The ruling on the latecomer saying the closing salam with the imam while forgetting

Question:
If I am praying Maghrib and I am a latecomer by one unit of prayer, and when the imam says the closing salam, I say it with him while forgetting, what do I do after saying the opening takbir? What do I do? And that is because after saying the opening takbir and performing the third unit of prayer, do I prostrate after the salam or before it? May Allah reward you with good.

Answer:
If you missed a unit of prayer, when your imam says the salam, you stand up and perform that unit; you do not say the salam with him. And if you say the salam with him while forgetting, there is no blame on you. You stand up and complete your prayer, then it is better to prostrate for forgetfulness after the salam. You prostrate for forgetfulness after you say the salam, prostrating two prostrations for forgetfulness, because your saying the salam with your imam out of forgetfulness does not harm. It is not permissible for you to do that intentionally. If you do it intentionally while you know the legal ruling, the prayer is invalid. But if you were ignorant or forgetting, and then you realized it, you complete the prayer, then it is better to prostrate for forgetfulness after the salam, two prostrations for your saying the salam with the imam while forgetting. And if you prostrate for forgetfulness before the salam, before your saying the salam, if you have made up what is required of you, there is no blame on you in that. But the better in such a case is that the prostration for forgetfulness be after the salam. Yes.

The presenter : May Allah reward you with good, and may He do you good.