If the imam prays without ablution while forgetting, and remembers after finishing, what is the ruling on his prayer and the prayer of the congregation?

The questioner : Well, in this issue, if he does not remember until after the prayer is finished, meaning after he has prayed, one of the people says, "O imam, did you perform ablution?" and he says, "No, I did not perform ablution," then the prayer is ruined. But as for the meat, I and you are like the meat of a sheep, and this means the prayer is invalid.

The Shaykh : Because he prayed without it, so what does he do now?

The questioner : He performs it.

The Shaykh : He must perform ablution and pray, and the prayer of the believers.

The questioner : Correct.

The Shaykh : is valid, even according to those who say that if he remembers during the prayer, the prayer of the ma'mum (one praying behind the imam) does not become invalid, because it has ended and its connection to the imam's prayer was severed before the presence of the invalidating factor in the prayer. This indicates the validity of the opinion that says if he becomes aware of the invalidating factor during the prayer, the prayer of the ma'mum does not become invalid.