What does Psalm 50:20 mean?

The wicked being judged by God (Psalm 50:1–6) pretended to be righteous (Psalm 50:8–9), but they were hypocritical. This psalm notes many ways in which Israel was living in deep contradiction to their claims of faith (Psalm 50:16–17). Specific examples included wallowing in lies, evil speech, and adultery (Psalm 50:18–19). Here, that evil speech extends to "slander." This type of speech is harmful as well as untrue, or at least unfair. It implies a sense of division and disruption.

Because slander is lying—either literally or through distortion—it fits a prohibition given in the Ten Commandments (Exodus 20:16). "To bear false witness" implies claiming something about another which is not true: a common aspect of "slander." That Israel would do such things is sinful enough. To act that way towards one's own family—their "brother"—is a sign of deep depravity.

Proverbs 10:18 pronounces, "Whoever utters slander is a fool." The apostle Paul and his associates were targets of slander, but they did not retaliate. Paul writes in 1 Corinthians 4:13, "when slandered, we entreat." They offered a gentle answer to false words.