▼sn The passive participle is figurative (implied comparison with “binding”); it means that folly forms part of a child’s nature (J. H. Greenstone, Proverbs, 238).

▼tn The “heart of a child” (לֶב־נָעַר, lev naʿar) refers here to the natural inclination of a child to foolishness. The younger child is meant in this context, but the word can include youth. R. N. Whybray suggests that this idea might be described as a doctrine of “original folly” (Proverbs [CBC], 125). Cf. TEV “Children just naturally do silly, careless things.”

▼tn The word “rod” is a metonymy of adjunct; it represents physical chastening for direction or punishment, to suppress folly and develop potential. The genitive (“discipline”) may be taken as an attributive genitive (“a chastening rod”) or an objective genitive, (“a rod [= punishment] that brings about correction/discipline”).