Answered by Shaykh Amjad Rasheed
Does someone who prays an obligatory prayer with a group outside the mosque (such as, for example, at home) attain the merit of the group prayer that is mentioned in hadiths even if the group prayer consists only of himself and his wife?
Yes, whoever prays a group prayer outside the mosque gains its reward as established in hadiths such as, “The group prayer is better than the individual prayer by 27 degrees.” However, the reward of praying with the group in the mosque is more complete, as has been explicitly stated by Imam Nawawi in al-Rawda. The group prayer can be performed by two people–the imam and the follower–even if the the follower is one’s wife, in which case both gain the reward of the group prayer.
الجواب : نعم من صلى الفرض جماعةً ولو في غير المسجد حاز فضيلتها الثابتة في الأحاديث كحديث: ” صلاةُ الجماعة خير من صلاة الفذ بسبع وعشرين درجة “. لكنَّ ثوابَ الجماعة في المسجد أتمُّ كما صرح بذلك كله الإمام النووي في “الروضة” . وتحصل صلاةُ الجماعة باثنين إمام ومأموم ولو كان المأمومُ هو الزوجة فيحصلان ثواب الجماعة .