{خالدين فيها}
Abiding therein forever; they shall neither die nor be expelled. It is a circumstantial qualifier (*hal*) for the pronoun in {يُجْزَوْنَ} (they are rewarded), or alternatively, for the pronoun in {يُلَقَّوْنَ} (they are met/greeted).
{حَسُنَتْ مُسْتَقَرًّا وَمُقَامًا}
An excellent abode and a place to dwell. This stands in opposition to {سَاءَتْ مُسْتَقَرًّا} (an evil abode), both in meaning and in grammatical parsing; so take heed and do not be neglectful.
