Albert Barnes Commentary Proverbs 14:8

"The wisdom of the prudent is to understand his way; But the folly of fools is deceit." — Proverbs 14:8 (ASV)

The Hebrew counterpart to the Greek “Know thyself.” “The highest wisdom is for a person to understand his own way. The most extreme folly is self-deceit.” The word “deceit” may, however, involve fraud practiced upon others. The folly of fools shows itself then in their ceaseless effort to deceive.