The Torah commands in Parashat Kedoshim (Vayikra 19:18), “Ve’lo Titor” – that we may not harbor feelings of resentment in our heart toward someone who has wronged us. As opposed to the prohibition of “Lo Tikom” (“You shall not take revenge”), which forbids actually avenging wrongdoing, the prohibition of “Ve’lo titor” forbids bearing a grudge in one’s heart, even without doing anything to the person who has wronged us. The classic example given by the Sages is a person who asked if he could borrow his fellow’s sickle, and his fellow refused, and then, the next day, that fellow asks him if he could borrow his axe. The prohibition against revenge forbids the man from refusing to lend him his axe to avenge his refusal to lend his sickle the previous day. The prohibition of “Ve’lo Titor” forbids the man from saying as he lends the axe, “I’m not like you; you refused to lend to me, but I am lending to you.” Even though he agrees to lend his axe, nevertheless, he has violated the command of “Ve’lo Titor” by harboring resentment, as expressed in his hostile remark. The rationale underlying this Misva, the Sefer Ha’hinuch explains, is the same rationale which he presented to explain the previous command, the command against taking revenge. One of the basic tenets of Jewish faith is that everything which happens to us has been willed by G-d, and therefore, if somebody wrongs us, we must recognize that this happened because Hashem decided that this must happen. It is therefore senseless to harbor negative feelings toward the person who wronged us, who was but G-d’s messenger. We should instead recognize that Hashem had this happen as a call to introspect and strive to improve our conduct. The Torah forbids taking revenge and even harboring resentment so that we realize that everything we experience has been brought about by G-d for a reason. This prohibition applies in all times, in all places, and to both men and women. One who violates this command is not liable to Malkut, because this violation is committed in one’s mind and heart, without performing an action. As mentioned, the example given by the Sages is a monetary offense, when a person refused to lend something to his fellow. The later Rabbis addressed the question of whether the prohibitions against taking revenge and bearing a grudge apply also to other kinds of offenses, such as if a person caused his fellow physical harm, or embarrassed him. Would it be permissible for the victim in these cases to take revenge or harbor feelings of resentment? Some Rishonim indicate that in such situations, the victim would, in fact, be allowed to take revenge or bear a grudge. The Sefer Ha’hinuch, however, implies otherwise. In defining the prohibition against taking revenge, he speaks of a case where someone did any sort of wrong to his fellow (“She’si’aro Be’ehad Min Ha’derachim”) – suggesting that even if one caused his fellow physical harm or embarrassment, the victim may not take revenge or bear a grudge. The Hafetz Haim, in his work on the laws of forbidden speech (introduction, Be’er Mayim Haim notes), shows that the Rambam, too, ruled stringently in this regard, and felt that these prohibitions apply in all cases of wrongdoing, and not just in situations of financial damage. In light of these different opinions, the Hafetz Haim writes, we apply the famous rule of “Safek De’Orayta Le’humra” – that we must act stringently when faced with uncertainty with regard to a Biblical law. As the Torah commands of “Lo Tikom” and “Ve’lo Titor” are at stake, we must follow the stringent opinion and refrain from revenge and resentment in all situations, regardless of what kind of wrong we suffered.