These are murmurers - The word here used does not elsewhere occur, though the word “murmur” is frequent, Matthew 20:11; Luke 5:30; John 6:41, John 6:43, John 6:61; John 7:32; 1 Corinthians 10:10. Compare John 7:12; Acts 6:1; Philippians 2:14; 1 Peter 4:9. The sense is that of repining or complaining under the allotments of Providence, or finding fault with God’s plans, and purposes, and doings.
Complainers - Literally, finding fault with one’s own lot (μεμψίμοιροι mempsimoiroi.) The word does not elsewhere occur in the New Testament; the thing often occurs in this world. Nothing is more common than for men to complain of their lot; to think that it is hard; to compare theirs with that of others, and to blame God for not having made their circumstances different. The poor complain that they are not rich like others; the sick that they are not well; the enslaved that they are not free; the bereaved that they are deprived of friends; the ugly that they are not beautiful; those in humble life that their lot was not cast among the great and the frivolous. The virtue that is opposed to this is “contentment” - a virtue of inestimable value. See the notes at Philippians 4:11.
Walking after their own lusts - Giving unlimited indulgence to their appetites and passions. See the notes at 2 Peter 3:3.
And their mouth speaketh great swelling words - Notes at 2 Peter 2:18.
Having men’s persons in admiration - Showing great respect to certain persons, particularly the rich and the great. The idea is, that they were not “just” in the esteem which they had for others, or that they did not appreciate them according to their real worth, but paid special attention to one class in order to promote their selfish ends.
Because of advantage - Because they hoped to derive some benefit to themselves.