2 Peter 2:6

πόλεις Σοδόμων. The genitive, as in urbs Romae, is of apposition.

τεφρώσας. Examples are quoted from Dion Cassius describing an eruption of Vesuvius, and from Lycophron (who in his so-called play the Alexandra or Cassandra heaps together all the obscure words he can find): l. 227 τεφρώσας γυῖα Λημναίῳ πυρί. This means “reduce to ashes.” The passage in Dion Cass. means “covered with ashes.”

καταστροφῇ κατέκρινεν is the reading of the large mass of authorities, BC alone omitting καταστροφῇ, and P reading κατέστρεψεν. The meaning would be either “condemned by overthrowing” or “condemned to overthrow” (the latter unclassical, but paralleled by Matthew 20:18 κατακρίνουσιν αὐτὸν θανάτῳ). I think the word should be restored to the text.

ὑπόδειγμα μελλόντων� = Jude πρόκεινται δεῖγμα πυρὸς αἰωνίου. For ἀσεβέσιν (BP) the bulk of authorities read ἀσεβεῖν, induced probably by the presence of μελλόντων, with which an infinitive is expected. A good parallel to these verses is in 3Ma 2:4-5 (in a prayer of the high-priest Simon):

Σὺ τοὺς ἔμπροσθεν�, ἐπαγαγὼν (cf. ἐπάξας) αὐτοῖς�. Σὺ τοὺς ὑπερηφανίαν ἐργαζομένους Σοδομίτας … πυρὶ καὶ θείῳ κατέφλεξας, παράδειγμα τοῖς ἐπιγενομένοις καταστήσας.

The date of 3 Macc. is uncertain, but it is a Jewish book, probably written about the Christian era.