Lit., are in luxury. On ὑπάρχοντες, are, see on Jam 2:15. On τρυφῇ, luxury, see on 2Pe 2:13, the only other place where it occurs. Compare the kindred verb τρυφάω, to live in luxury, Jam 5:5.
Kings' courts (βασιλείοις)
Only here in New Testament. Often rendered palaces. Sometimes, in later Greek, applied to a capital or royal city, a royal treasury, and a royal diadem.