Making up for the missed Salah in order

Q 7: A man on a journey delayed the Maghrib (Sunset) Prayer; and when he arrived, he joined the Imam (the one who leads congregational Prayer) who was offering the `Isha' (Night) Prayer. What should he do? Should he offer the `Isha' Prayer behind the Imam then offer the Maghrib Prayer or is it obligatory to observe the order of Prayers?

A: Anyone who misses the Maghrib Prayer and enters a Masjid (mosque) to find the Imam leading the `Isha Prayer is entitled to join the Imam with the intention of offering the Maghrib Prayer. When the third Rak`ah (unit of Prayer) is over, they should (Part No. 5; Page No. 96) sit and recite the last Tashahhud (a recitation in the sitting position in the second/last unit of Prayer). Then, they can either say Taslim (salutation of peace ending the Prayer) or wait for the Imam until he finishes the fourth Rak`ah of the `Isha' Prayer to follow him in Taslim. However, it is preferable for the person to offer the Maghrib Prayer alone and then join the Imam in the remaining Rak`ahs of the congregational `Isha' Prayer.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.