Is it obligatory for a resident performing the prayer of collection (jama'an) to pray only the obligatory (fard) prayers, or is it permissible for him to pray the emphasized Sunnah (confirmed voluntary) prayers?

It is permissible for a resident to combine prayers due to an excuse such as illness or rain. He may pray the regular supererogatory (Sunnah) prayers, but they are not obligatory. If he combines Dhuhr and Asr, he should pray the pre-Dhuhr Sunnah, then Dhuhr and Asr, then the post-Dhuhr Sunnah and the Asr Sunnah. If he combines Maghrib and Isha, he should pray Maghrib and Isha, then the Maghrib Sunnah, then the Isha Sunnah, then Witr.