John Gills Exposition of the Bible Commentary - Proverbs 14:9
Fools make a mock at sin ,.... At sinful actions, their own or others; they make light of them, a jest of them, call evil good, and good evil; take pleasure in doing them themselves, and in those that do them; yea, sport themselves with the mischief that arises from them unto others; they make a mock at reproofs for them, and scoff at those that instruct and rebuke them; and laugh at a future state, and an awful judgment they are warned of, and in a scoffing manner say, "where is the promise... read more
Matthew Henry's Complete Commentary - Proverbs 14:9
See here, 1. How wicked people are hardened in their wickedness: they make a mock at sin. They make a laughing matter of the sins of others, making themselves and their companions merry with that for which they should mourn, and they make a light matter of their own sins, both when they are tempted to sin and when they have committed it; they call evil good and good evil (Isa. 5:20), turn it off with a jest, rush into sin (Jer. 8:6) and say they shall have peace though they go on. They care... read more