The ruling on the prayer of one who returns to the middle tashahhud after straightening up

Question:
This questioner is from Oman, Jordan. He says in this question: Your Eminence, what is the ruling on the prayer if the imam forgets to sit for the first tashahhud in a four-rak'ah prayer, after he has straightened up to stand for the third rak'ah, and the worshippers opened the way for the imam, so he descended to the tashahhud after straightening up?

Answer:
What is prescribed for him after straightening up is to proceed, and for them to follow him, and to prostrate for forgetfulness. However, if he returns, it does not harm him—if Allah wills. If he returns, they sit with him, and they prostrate for forgetfulness as well. But the better course is that if he has fully stood up, he proceeds and prostrates for forgetfulness after that, two prostrations before he says the closing salam, and they follow him. But if he remembers after he has stood up and returns, then they sit with him, and he has to prostrate for forgetfulness.
As for if he remembers while standing up in the act of rising, he is obligated to sit until he completes the first tashahhud, and they are with him in that as well. But if he has fully stood up, this is the place of dislike according to some scholars of knowledge. And in the hadith of al-Mughirah in this meaning, there is what indicates that if he has fully stood up, he does not return. As for if he has begun the recitation, he has no right to return, but rather he continues, and he has to prostrate for forgetfulness only, and praise be to Allah. Yes.

The presenter: May Allah reward you, Your Eminence.