John Gill's Exposition of the Whole Bible
Proverbs 24:9
The thoughts of foolishness [is] sin,.... The thought of sin is sin e, before it comes into action; the motions of sin in the mind, the workings of corrupt nature in the heart, the sinful desires of the flesh and of the mind: these are forbidden and condemned by the law of God as sin, which says, "Thou shall not covet", Exodus 20:17, and stand in need of pardoning grace and mercy; see Romans 7:5. Or, "the thoughts of a foolish man are sin" f; that is, of a wicked man; in all whose thoughts God is not, but sin is; the imagination of the thoughts of his heart is evil, and that continually; he thinks of nothing else but sin, Genesis 6:5;
and the scorner [is] an abomination to men; who not only thinks ill of divine things, and despises them in his heart, which is only known to God; but scoffs at them with his lips, makes a jest of all that is good, derides religion and religious men; and to such he is an abomination: and indeed one that is proud and haughty, scorner is his name, and that deals in proud wrath, and scorns all around him, in whatsoever company he comes, and that ridicules every person, and every thing that is said in conversation, is usually hated and abhorred by all sorts of men.
e "Nam scelus intra se tacitum qui cogitat ullum, facti crimen habet", Juvenal. Satyr. 13. v. 209, 210. f אולת "stulti", Pagninus, Junius Tremellius, Mercerus, Piscator, Gejerus.