Proverbs 23:9

“Speak not in the ears of a fool, etc.] For it is only beating the air, and speaking to the wind; it is casting pearls before swine, and that which is holy to dogs. By the “fool” is meant a wicked man, one abandoned to sin, and hardened in it; that scoffs at all admonitions and reproofs, that derides the word, and the preachers of it, and makes a mock at all good men, and everything they say; and therefore what is serious and sacred should not be said to them, since it only becomes the object of their banter and ridicule; for he will despise the wisdom of thy words; not only the words of doctrine, reproof, and correction, but the “wisdom” of them; or let them be ever so wisely spoken; for if…”

“(Compare Pro 9:8). "Cast not your pearls before swine" (Mat 7:6).”

“The “fool” here is one willfully and persistently deaf to it, almost identical with the scorner. return to 'Top of Page'”

“Of a fool - Cast not away good counsels upon incorrigible sinners. Proverbs 23:10”

“23:9 Saying 9: Fools ignore advice (cp. 9:7-12; 10:18), so the wise do not waste their breath (see Matt 7:6).”

“Speak: Pro 9:7, Pro 9:8, Pro 26:4, Pro 26:5; Isa 36:21; Mat 7:6; Act 13:45, Act 13:46, Act 28:25-28 he: Luk 16:14; Joh 8:52, Joh 9:30-34, Joh 9:40, Joh 10:20; Act 17:18, Act 17:32; Co1 1:21-24; Co1 4:10-13 Proverbs 23:10”

“Another case in which good words are lost: Speak not to the ears of a fool, For he will despise the wisdom of thy words. To speak in the ears of any one, does not mean to whisper to him, to so to speak that it is distinctly perceived. כּסיל, as we have no often explained, is the intellectually heavy and dull, like pinguis and tardus; Arab. balyd, clumsy, intellectually immoveable (cf. bld, the place where one places himself firmly down, which one makes his point of gravity). The heart of such an one is covered over ( Psa 119:70), as with grease, against all impressions of better knowledge; he has for the knowledge which the words spoken design to impart to him, no susceptibility, no mind,…”