Question
I entered the mosque to perform the Maghrib prayer in congregation, and I found the imam concluding the prayer. Then he announced that he would pray the Isha prayer combined with Maghrib due to the rain. I intended to pray Maghrib following the imam who is praying Isha, and I concluded my prayer after the third rak'ah while the imam stood for the fourth rak'ah. Is what I did correct?
Answer
I say, and with God's help: The prayer is not valid between the imam and the follower if they differ, as in the situation you mentioned, and you must repeat the Maghrib prayer; for it is invalid due to the intention of praying after the Isha prayer, and God knows best.