The Torah stresses the importance of treating the most vulnerable members of society in an exceedingly gentle and sensitive fashion, as the pasuk states, "You shall not wrong (lo tonu) the convert etc. You shall not mistreat any orphan or widow" (Shemos 22, 20-21). However, in fact this prohibition applies not only to converts, orphans, and widows, but extends to other people within the community as well, as we are told, "And do not wrong (v'lo tonu) one another" (Vayikra 25, 17). The Gemara (Bava Metziah 58b) posits that since a general prohibition against cheating others is already recorded in the earlier pasuk, "you shall not wrong (al tonu) one another" (Vayikra 25, 14), this latter prohibition must be directed towards additional forms of mistreatment, specifically hurtful speech or even verbal abuse, known as onaas devarim.
Rabbi Avraham Pam once observed, "Over the past few years, so much has been written and said concerning the sin of speaking lashon hara etc. However, there is another sin relating to speech about which very little is spoken, and that is onaas devarim." Rav Pam continued and reflected upon the irony of this phenomenon. Lashon hara is evil speech which is perpetrated about someone else, usually in their absence. However, the prohibition of onaas devarim relates to hurtful and even abusive remarks that are made directly to the victim, in their presence, which can obviously be all the more offensive and traumatic, and therefore arguably deserves greater attention and vigilance. Indeed, we find certain instances in halacha where a verbal assault is treated more severely than a physical attack, which of course is also a heinous crime.
For example, while it is well established, that a doctor can cause a wound for a medical or rehabilitative purpose, cruel and insulting comments are prohibited even when one has the best of intentions. The Gemara (Bava Basra 16a) attests that Peninah taunted Chanah (Shmuel 1, 1) about her childlessness only in order to encourage her to daven with greater intensity. Nonetheless, despite her noble objective, the pain Peninah caused Chanah with her words was intolerable, and she was ultimately punished bitterly as a result. The Vilna Gaon suggests that this lesson is alluded to in the language of the ensuing pasuk, "If you dare cause him pain, so that he shall cry out to Me, I shall surely hear his cry" (Shemos 22, 22). Even if one only caused grief to the orphan or the widow, for their own benefit, "so that he shall cry out" to Hashem with greater devotion, it is still forbidden.
Similarly, the Baal Haturim (Breishis 21, 10) claims that the Jewish people were exiled specifically to the land of Egypt as result of the unforgiving manner in which Sarah unceremoniously evicted Hagar the Egyptian from her home, as the pasuk states, "She said to Avraham, 'Cast out that slave-woman and her son.'" Rav Shlomo Kluger alleges that the familiar statement of the Pesach Haggadah, "And he went down to Egypt forced by the word," does not refer to the "word" of Hashem, but rather to Sarah's callous words towards Hagar. Even though Sarah acted aggressively for the sole purpose of preserving the spiritual integrity of Yitzchok, her descendants were punished for her abrasive tone. Rav Chaim Shmuelevitz (Sichos Mussar) compares a person who speaks harshly to others to one who ventures into an ominous blaze. No matter how virtuous their intentions, they will inevitably become burned.
In addition, the Ramban (Shemos 21, 15) notes that the method of capital punishment administered for cursing a parent is more stringent than the death penalty which accompanies striking a parent. Rav Eliyahu Baruch Finkel proposes that this reflects the reality that often the emotional wounds of betrayal and isolation created by the denunciations and condemnations of one's own child, can be more profound and painful than a physical bruise or gash. The Maharal (Nesivos Olam) explains more deeply, that verbal assaults can be so pernicious and poignant because they are not targeted at the external body which is naturally trained to heal over time, but rather with intent to harm the soul of a person, to diminish their self-worth, significance, and contribution. For this reason, the recovery process from the emotional wounds of hurtful comments can be complex and prolonged, and can never be confined to a financial settlement or mitigated by monetary compensation.
One of the subtler differences between the two competing versions of musical notes (trop) that accompany the ten commandments, known as the taam tachton and the taam elyon, is that in the taam tachton there is a pasach underneath the letter tzadi in the word "lo tirtzach" - "do not murder", while in the taam elyon there is a komatz. The word "pasach" is related to the word "lifsoach" - "to open," and the word komatz is associated with "likmotz" - "to close." The Chasam Sofer suggests that this teaches us that in order to avoid verbal murder, and to preserve the dignity and wellbeing of others, we need to be able to close our mouths and refrain from speaking harshly and in a hurtful manner towards others. At the same time, when we witness verbal abuse, we must summon the courage and strength to open our mouths, to protest, protect, and defend the lives and self-esteem of the innocent and all those who need our help.