"The rod of correction gives wisdom" (29:15). What does the saying say, and what doesn't it?

The saying has two halves: "The rod of correction gives wisdom, but a child left to himself causes shame to his mother" (29:15). The first says what gives wisdom. In Hebrew the rod of correction is two nouns joined by and: shevet, the rod, and tokhachat, the word of often rebuked in 29:1 (tap rod, correction). The second half says what a child left to himself brings his mother: shame. Two sayings later comes "Correct your son, and he will give you peace; yes, he will bring delight to your soul" (29:17) (tap Correct). It doesn't name the rod, and in Hebrew its first two words open one other saying: "Discipline your son, for there is hope" (Proverbs 19:18); the notes on Proverbs 19 look at it. The notes on Proverbs 13 look at "One who spares the rod hates his son" (Proverbs 13:24), the notes on Proverbs 22 at "Folly is bound up in the heart of a child; the rod of discipline drives it far from him" (Proverbs 22:15), and the rod comes in Proverbs 23:13-14 too. 29:17 is a saying of what correction brings, and these notes don't make it a guarantee about any child. These notes explain 29:15 and 29:17 only from their own words; they don't apply them to any modern practice, law or debate, or say how anyone should discipline a child. If this saying touches anyone harmed at home, make room to talk, and help them find someone they trust to talk to further, such as a pastor or a counselor.