Question # 519: Is it permissible to observe solatul asr behind an imam observing solatul magrib?
bismi-llahi r-raḥmani r-raḥīm,
Assalamu ‘laikum warahmatullahi wabarakatuh,
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Shorter Answer: It is not permissible to observe ‘Asr prayer behind an Imam observing Maghrib prayer; rather one should pray Maghrib with the Imam, then pray ‘Asr afterward, as agreed upon by all leading scholars and he does not have to repeat the Maghrib prayer after praying ‘Asr according to the most correct opinion.
Long Answer: Sheikh al-Islam Ibn Taimiyyah said that he should pray Maghrib with the Imam (prayer leader), then pray ‘Asr afterward, as agreed upon by all leading scholars. The question of does he repeat Maghrib has two scholarly opinions: the first is that he repeats. This is the saying of Ibn Umar, Malik, Abi Hanifa, and Ahmad in what is most well-known about this issue. The second opinion is that he does not repeat. This is the saying of Ibn Abbas, the Shafi’i madhab, and the second opinion of Imam Ahmad’s school of thought. The latter is more correct, for Allah (سبحانه و تعالى) did not make it obligatory on the person to pray a salaat twice if he has feared Allah as much as he can [Allah knows best]). (From the book ‘What Should You Do in the Following Situations… ?’ by Majmooa Fatawi Ibn Taimiyyah)
(The above reply is based on various answers on similar topics provided by Islamqa.info)
Allahu A’lam (Allah (سبحانه و تعالى) knows best) and all Perfections belong to Allah, and all mistakes belong to me alone. May Allah (سبحانه و تعالى) forgive me, Ameen.