Albert Barnes Commentary Proverbs 20:11

"Even a child maketh himself known by his doings, Whether his work be pure, and whether it be right." — Proverbs 20:11 (ASV)

The graces or the faults of children are not trifles. “The child is father of the man”; and the earliest actions are prophecies of the future, whether it will be pure and right, or unclean and evil.