The sage again advocated discipline. Beating with a rod is not the only form of discipline advocated in Proverbs. It is simply one form used here as a poetic parallel to discipline (Heb. musar, moral correction). Other forms of discipline (reproof, temporary isolation, "grounding," etc.) may be more appropriate in some situations with children of differing ages and temperaments. These verses assure the parent that the child will not only survive the discipline, but he or she will survive because of it. [source][source][source]
"The idea is that discipline helps the child to live a full life; if he dies (prematurely), it would be a consequence of not being trained. In Proverbs such a death might be moral and social as well as physical." [1][source]
"Severe discipline is not cruel, but to withhold it from callous youth is.... However, the cleansing rod must be applied with warmth, affection, and respect for the youth. Warmth and affection, not steely discipline, characterize the father"s lectures (cf. Proverbs 4:1-9). Parents who brutalize their children cannot hide behind the rod doctrine of Proverbs." [2][source]