Bede

Even by his pursuits, a youth is known, etc. For whomsoever you see striving for virtues, modesty, continence, listening to the wise, and observing the commandments of God, especially humility and simplicity, know that his works are pure and right. But whomsoever you find taking a contrary course, recognize him as a man of an impure and crooked heart, and either correct and chastise him or if you cannot, avoid and shun him, lest you yourself be corrupted by him. …

Commentary on Proverbs ↗