John Gills Exposition of the Bible Commentary - Proverbs 14:3
In the mouth of the foolish is a rod of pride ,.... A proud tongue, or a tongue speaking proud and haughty things; with which foolish or wicked men smite others and wound and hurt their reputation and credit, and in the issue hurt themselves also; their tongue is not only a rod to others, but a scourge to themselves, or is the cause of evil coming upon them; such was the tongue of Pharaoh, as Jarchi on the place observes, Exodus 5:2 ; and of those the psalmist speaks of, Psalm 73:9 ;... read more
Matthew Henry's Complete Commentary - Proverbs 14:3
See here, 1. A proud fool exposing himself. Where there is pride in the heart, and no wisdom in the head to suppress it, it commonly shows itself in the words: In the mouth there is pride, proud boasting, proud censuring, proud scorning, proud commanding and giving law; this is the rod, or branch, of pride; the word is used only here and Isa. 11:1. It grows from that root of bitterness which is in the heart; it is a rod from that stem. The root must be plucked up, or we cannot conquer this... read more