What is the ruling on joining a congregation that is praying 'Isha' with the intention of praying Maghrib?
Machine translationRead the Arabic original
Question:
What should I do if I join a congregation while they are praying 'Isha', and I intend to pray Maghrib when they stand for the fourth rak'ah?
Answer:
It is better for you to pray Maghrib alone. Do not pray it behind someone who is praying 'Isha', because the two prayers differ; this one is four units and that one is three units, so the two prayers are different. Therefore, it is better that you pray it alone or with a congregation like yours who missed the Maghrib prayer. But if you did this and prayed it behind someone who is praying 'Isha', the prayer is valid. Then, when they stand for the fourth unit, you have a choice: if you wish, you perform the final tashahhud and say the taslim for yourself, intending to pray alone; or if you wish, you wait sitting until the imam says the taslim, and you say the taslim with him. Yes.
What should I do if I join a congregation while they are praying 'Isha', and I intend to pray Maghrib when they stand for the fourth rak'ah?
Answer:
It is better for you to pray Maghrib alone. Do not pray it behind someone who is praying 'Isha', because the two prayers differ; this one is four units and that one is three units, so the two prayers are different. Therefore, it is better that you pray it alone or with a congregation like yours who missed the Maghrib prayer. But if you did this and prayed it behind someone who is praying 'Isha', the prayer is valid. Then, when they stand for the fourth unit, you have a choice: if you wish, you perform the final tashahhud and say the taslim for yourself, intending to pray alone; or if you wish, you wait sitting until the imam says the taslim, and you say the taslim with him. Yes.
Source
قناة «العلامة الدكتور صالح الفوزان»، ما حكم الدخول مع جماعة يُصلون العشاء بنية صلاة المغرب؟ #فتاوى الفوزان — youtube.com
The Arabic text is a machine transcription of the audio recording.