A traveler who did not pray Maghrib until the time of 'Isha' passed by the people of a village while they were praying 'Isha'

The questioner : Praise be to Allah, Lord of the worlds, and blessings and peace be upon our Prophet Muhammad, and upon his family and all his Companions.
The questioner says: A traveler did not pray Maghrib until the time of 'Isha', so he passed by the people of a village while they were praying 'Isha'. Another man from the village prayed with them with the intention of Maghrib, thinking that they were praying Maghrib. What is the status of each of these two men? Please issue a ruling on this, citing the evidence, and may Allah reward you with good.

The Shaykh : Praise be to Allah, and blessings and peace be upon the Messenger of Allah, his family, his Companions, and whoever supports him.
The truth is that we do not have a text regarding this specific issue about which the question was asked; rather, it is derived through a degree of deduction and independent legal reasoning. We say that it is established in the Sunnah that a difference in intention between the follower and the imam does not affect the validity of the prayer or the validity of following. For example, there is the prayer of Mu'adh ibn Jabal of the last 'Isha' behind the Prophet (peace and blessings be upon him), and then his prayer of it with his people. As it came in "Sahih al-Bukhari," it was a voluntary prayer for him and an obligatory prayer for those behind him. Also, there are some authentic hadiths regarding one of the methods of the Prophet's (peace and blessings be upon him) prayer of fear with his Companions. Among these is that he would pray two rak'ahs with the first group, then say the closing salam with them. These people would then proceed to the ranks of the other group so that they could come and pray two rak'ahs behind the Prophet (peace and blessings be upon him). Naturally, the first two rak'ahs would be the obligatory prayer for the Messenger (peace be upon him), and the last two rak'ahs with the other group would be a voluntary prayer. And so on; there may be other examples that I do not recall at the moment. Also, we must mention here the incident of that Bedouin who was working in the open fields during the day and would come in the evening to pray behind Mu'adh (may Allah be pleased with him). One day, when he followed him in the last 'Isha' prayer and heard him begin Surat al-Baqarah, he thought, or it was suggested to him, that this recitation would be very long, and very long indeed for him. So he cut off the prayer behind Mu'adh and prayed alone.
When we look at these texts, we can then say that the prayer of this traveler or that resident who followed the imam while he was praying 'Isha', and each of them assumed that he was praying Maghrib, only to find out that he was actually praying 'Isha', is as follows: In this case, if he caught up with the imam in the first rak'ah, then when the imam stands up for the fourth rak'ah, each of them should intend to separate and cut off following the imam, so that he sits for the final tashahhud at the end of the third rak'ah for him, and says the salam. Then he stands up and follows the imam for whatever of the 'Isha' prayer he catches up with. This is what appears to me as the answer to this question.
Yes.

The questioner : The traveler knows that that imam is praying 'Isha', and he delayed Maghrib. So he entered with the congregation; does he enter with them with the intention of Maghrib?

The Shaykh : Of course, it is not permissible to delay the Maghrib prayer until after the 'Isha' prayer. Rather, he follows him, then intends to separate, as I said earlier, when the imam stands up for the fourth rak'ah.

The questioner : Some scholars said: He enters with them with the intention of a voluntary prayer; he prays 'Isha' with them as a voluntary prayer for him, then prays Maghrib, then 'Isha'.

The Shaykh : Why?

The questioner : I do not know; what is the validity of this opinion, or?

The Shaykh : This is what I presented to you. I presented the evidence I presented to clarify that a difference in intention between the follower and the imam does not harm the validity of the prayer. If he is praying Maghrib and the imam is praying 'Isha', it is even more likely that this prayer is valid than the prayer of those performing a voluntary prayer behind those performing an obligatory prayer being valid. The only thing in the matter is that he needs a means in the subject; which is that he intends to separate.

The questioner : May Allah reward you with good.

The Shaykh : And beware of that.