ISB ~ 2 Thessalonians 1 v10

that day:The final “day of the Lord” (2:2). his saints: Or, “his holy ones”. This could refer to the redeemed People of God (Jude), but it is more likely a reference to the holy angels (1:7; Ps 89:7). Either way, their appearance in glory will magnify the glory of Christ, whose divine splendor shines through them (Phil 3:21; Col 3:4). See note on 1 Thess 3:13.