תהלים, פרק נ״ח, פסוק ה׳

The destructive power of malicious words and baseless hatred mirrors the deadly, unforgiving nature of a venomous snake. Wicked individuals harbor a lethal poison within them. When consumed by anger, they project this verbal venom to harm and destroy others [רש״י, רד״ק, מצודת דוד]. This toxicity is rooted in the ancient impurity introduced by the original serpent through lies and temptation, explaining why such individuals are so deeply attached to falsehood and harmful speech [אלשיך].

A snake does not bite for pleasure; it strikes out of deep-seated hostility and a preemptive fear of being attacked. Similarly, those who engage in slander often launch their attacks out of a fearful suspicion that others intend to harm them [מלבי״ם].

However, while ordinary snakes might be soothed and controlled by expert charmers, the wicked are likened to a particularly dangerous and vicious type of viper [מצודת ציון, מאירי, שטיינזלץ]. To ensure it can strike without interference, this viper actively makes itself deaf to the charmer's song [רד״ק, אבן עזרא, מצודת ציון]. According to tradition, as this snake ages, it naturally loses hearing in one ear and deliberately presses its remaining good ear into the dust to completely block out any calming incantations [רש״י].

This vivid imagery serves as a poetic reflection of the moral decay of the wicked. Their commitment to doing harm is so absolute that no moral instruction or rebuke can reach them, as they simply choose to block it out and ignore the truth [מצודת דוד]. In this way, they are considered even worse than the original serpent, which could at least be influenced to withhold its harm [אלשיך]. Even when offered gentle words of reassurance and clear proof of peaceful intentions, much like David proving his loyalty to Saul by sparing his life and only cutting the corner of his robe, the wicked refuse to listen. Instead, they seal their ears and stubbornly cling to their hatred [מלבי״ם].