What does Proverbs 12:23 mean?

This sentiment resembles Proverbs 17:28. The simple ability to keep control of one's tongue is a sign of wisdom. At the very least, it's better to say nothing than to babble out something foolish. Even if others might think poorly of the silent person, there is great advantage in being careful with one's words (Proverbs 10:19). An English proverb derived from these ideas says, "it's better to be silent and thought a fool than to speak and remove all doubt."

The word translated "prudent" here also means "sensible." A person with good sense does not feel led to ramble about what he knows, or thinks he knows. It is wise to keep quiet about one's knowledge, waiting for the right moment to offer good advice. In that restraint, a person shows humility. In contrast, a fool is quick to speak, likely to spit out something inane rather than helpful. Such a person is vain and ignorant (Proverbs 12:16). He mistakes his foolish counsel as wisdom that he feels compelled to share with anyone within earshot (Proverbs 13:16).