Slander and deceit carry a unique destructive power, prompting a sharp rhetorical question about the true purpose and result of spreading lies. When a person engages in malicious speech, they are challenged to deeply consider what they actually gain from their words.
The primary approach among commentators is that this serves as a direct confrontation with the slanderer, asking what benefit, profit, or pleasure can possibly be derived from spreading smears [מלבי״ם, ביאור שטיינזלץ]. Unlike other offenses that might yield a tangible reward or physical gain, speaking falsehoods offers the speaker absolutely nothing. Its only source is a twisted satisfaction and a malicious desire to cause harm to others. This concept also extends to a national scale [רד״ק, מאירי]. The challenge is directed at enemies and nations in exile, such as Babylon, who conceal their true plots. These nations pretend to be friends while spreading false accusations against the Israelites, yet they reap no actual benefit from their deceit.
Beyond the lack of practical gain, malicious speech triggers a severe spiritual consequence. A profound exchange takes place when slander is spoken [חומת אנך]. The person speaking the lies loses their own spiritual merits, which are instantly transferred to the victim. At the same time, the victim's sins are shifted and added to the slanderer's account. Recognizing the extreme danger of this spiritual damage, King David required a special prayer just to be saved from the destructive impact of harmful speech [אלשיך].
Taking a different perspective, a prominent Midrashic approach explains that the confrontation is not directed at the person, but at the tongue itself [רש״י, מצודת דוד, תורה תמימה]. God addresses the tongue directly, questioning what additional protections or barriers could possibly be given to it. Unlike other parts of the human body that stand upright and are exposed on the outside, the tongue lies flat and remains hidden within. Furthermore, God already enclosed it behind two natural guard walls: a wall of bone formed by the teeth, and a wall of flesh formed by the lips. The profound realization is that if these two physical barriers are not enough to stop a deceitful tongue, there is simply no further protection that can be added to keep it under control.