What does the ma'mum do if he comes for the Maghrib prayer and finds that they have combined it with the 'Isha' prayer, and he is in the first rak'ah?

The questioner : If the ma'mum goes to combine the Maghrib and 'Isha' prayers, he goes to pray Maghrib and finds them praying 'Isha', and he catches them in the first rak'ah, what does he do?

The Shaykh : He prays Maghrib while they are praying 'Isha. When the imam stands up for the fourth rak'ah of the 'Isha prayer, he intends to separate from him and sits for the tashahhud in the third rak'ah as far as he is concerned.

The questioner: Yes.

The Shaykh : Then he says the taslim, then he stands up and follows the 'Isha prayer with the imam. It may be the last rak'ah for the imam, but it is the first rak'ah for him.

The questioner : All right, if he sits and says the final taslim with them?

Another questioner : Wait for them, meaning.

The Shaykh : No, this has no basis.

The questioner : This was not a deviation from the imam, Shaykh?

The Shaykh : There is no deviation from the imam here, because the imam here is praying 'Isha and he is praying Maghrib. And it is not permissible to add to the obligatory prayer; if it were a voluntary prayer, he would have to follow him.