What does Proverbs 29:20 mean?

The book of Proverbs generally describes a "fool" as one who ignores godly truth and common sense (Proverbs 1:7; 3:1–5; 12:15). That attitude leads to tragedy, eventually. Either on earth, or in eternity, or both, the person who ignores the call of godly wisdom will suffer (Proverbs 8:32–36; 10:27). This proverb points out that a "typical" fool might find wisdom and change his ways before disaster strikes (Proverbs 8:5). If they're open to advice, they at least have a chance (Proverbs 26:12). The one who fails to control their temper, or regulate their words, is far more likely to suffer immediate, drastic consequences. James advises that "every person be quick to hear, slow to speak, slow to anger" (James 1:19).

Several lessons in this passage connect how one controls their speech to their level of wisdom (Proverbs 29:9, 11). This parallels Scripture's general teaching on the importance of regulating one's temper (Proverbs 14:17; 15:18; 21:23; Galatians 5:22–23; Titus 1:7). Blurting out angry words or reacting without thinking can lead to immediate, unfortunate consequences (Proverbs 18:6–7; 25:28).

Peter often spoke impulsively without thinking first. He rebuked Jesus when the Lord predicted His betrayal and death. He complained, "Far be it from you, Lord! This shall never happen to you" (Matthew 16:22). Jesus responded: "Get behind me, Satan! You are a hindrance to me. For you are not setting your mind on the things of God, but on the things of man" (Matthew 16:23). Later, Jesus noted that His disciples would all abandon Him when His enemies came to arrest Him (Matthew 26:31). Peter blurted out a claim that he'd never do such a thing (Matthew 26:33). Yet that same night, Peter claimed he didn't even know Jesus (Matthew 26:69–75).