The rod and reproof give wisdom: but a child left to himself bringeth his mother to shame.
– Proverbs 29:15
Verses 15-21 have some interspersed sayings pertaining to children and servants. This saying is in line with others in Proverbs concerning child training (Proverbs 13:24; 22:15; 23:13-14). The saying joins the rod and reproof as instruments to give wisdom. On balance, the primary tools parents should use is their law (Proverbs 1:8; 3:1; 4:2; 6:20; 28:7). The last line gives the alternative as bringing shame. All parents can do is correct foolishness and instruct in wisdom, but that doesn’t guarantee a child will be wise (Proverbs 13:1; 15:5; 17:10; 27:22). To leave off the effort will more often than not produce shame.