If I am offering Tahiyyat-ul-Masjid

Q 4: If a group of people enter a Masjid (mosque) while the Imam is offering Tarawih (special supererogatory night Prayer in Ramadan), should they offer the obligatory Salah of `Isha' (Night) Prayer in another congregation or offer it behind the Imam and when he concludes Salah, they complete the `Isha' Prayer?

A: To be on the safe side, they should offer Salah in congregation behind the person who knows the Qur'an amongst them to avoid the disagreement regarding the validity of offering the obligatory Salah behind an Imam who is offering a Nafilah (supererogatory) one. However, they may offer `Isha' (Night) Prayer following the Imam who offers Tarawih, their Salah will be valid and they will gain full reward of congregation according to the most preponderant view of scholars.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.