True morality extends far beyond external actions; it reaches into the deepest recesses of the human heart. The ultimate ethical standard demands not only that people treat one another with kindness, but that they uproot hidden animosity and view all of human society as a single, unified body.
The foundation of this standard rests on two interconnected prohibitions: taking revenge and bearing a grudge. The primary approach among commentators is that revenge is expressed through action, while bearing a grudge lives in the heart and in speech. Imagine a person who asks to borrow a sickle from a neighbor, only to be refused. The next day, the neighbor who refused asks to borrow an axe. If the first person denies the request, saying he will not lend his tool just as the neighbor refused him, this is an act of revenge. If, however, he hands over the axe but adds that he is lending it because he is not as petty as the neighbor, he is bearing a grudge by harboring enmity in his heart [רש״י, תורה תמימה, מלבי״ם].
This scenario raises a compelling question: why is the strict warning directed at the person seeking retaliation, rather than forbidding the initial refusal to lend the tool? The initial refusal stems from stinginess and an excessive attachment to personal property. While these are negative traits, they are not the focus here. The person seeking revenge, however, would have gladly lent the tool had he not been angry. His refusal is driven by a burning hatred and a deliberate desire to cause harm, which God strictly condemns [הטור הארוך, חזקוני, בכור שור].
These restrictions primarily govern matters of mutual aid and everyday kindness. When dealing with actual financial damage or physical harm, there is no obligation to simply let the matter go; rather, one must pursue justice and claim damages in a court of law [רמב״ן, רלב״ג]. Another perspective suggests that retaliation for slights to honor or property is forbidden because, in God's eyes, worldly disputes are akin to children's games, entirely unworthy of lasting enmity. The only justified retribution is God's response to those who actively try to lead others away from the path of the Torah [כלי יקר]. An exception is made for a Torah scholar, who is expected to fiercely defend the honor of the Torah against degradation. Yet, even this defensive anger must mirror snake venom that gradually loses its potency over time, with the ultimate goal being the spiritual correction of the offender [תורה תמימה, פני דוד, פרדס יוסף].
To illustrate the logic behind forbidding revenge, commentators offer the metaphor of a person slicing meat who accidentally cuts his own hand with the knife. It is unthinkable that the injured hand would turn around and strike the hand holding the knife. People should view their fellow human beings in the exact same way—as different limbs of a single body. Harming another person out of revenge is literally harming oneself [ירושלמי, תורה תמימה, העמק דבר].
By entirely negating hatred, the ethical framework naturally transitions into a positive obligation to love one's neighbor as oneself. While this is famously recognized as a great overarching principle of the Torah, it presents a profound difficulty. How can a person be commanded to love someone else exactly as much as they love themselves? This seems to contradict basic human nature, especially since Jewish law establishes that a person's own life takes precedence over another's. To resolve this, commentators explain that the directive is not to love the neighbor's actual physical self as one's own, but rather to love for the neighbor what one loves for oneself. A person should wish for their peers to achieve the exact same wealth, honor, and wisdom they desire for themselves, entirely free from jealousy [רמב״ן, מלבי״ם, בכור שור]. This love is measured in the quality of the relationship rather than its sheer quantity, demanding that one treat others with the same warmth, respect, and assistance they would hope to receive [שד״ל, הכתב והקבלה].
This concept was famously distilled into a negative formulation: whatever is hateful to you, do not do to your fellow. It is often easier for a person to avoid harming others when they realize how much they would suffer from receiving the same treatment [ספורנו, רש״ר הירש, חתם סופר]. However, an alternative perspective argues for an even greater foundational principle: the reality that humanity was created in the image of God. If the only metric for loving others is how much one loves oneself, a person with low self-esteem or self-destructive tendencies might feel justified in degrading others. Therefore, the true basis for human dignity must be the divine image inherent in every person [שפתי כהן, פירושי רד״צ הופמן]. Building on this, Chassidic thought explains that when a person elevates their perspective beyond the physical body and looks at the soul, they realize that all souls are carved from a single divine source. In truth, the individual and the neighbor share the exact same spiritual essence [חומש קה״ת].
This profound love is not left as an abstract philosophical ideal; it is translated into numerous practical laws. Driven by this standard of care, the sages established that if a person is sentenced to death by a court, they must be given the quickest and most humane execution possible. Similarly, a person is forbidden to marry a woman before seeing her, lest he later discover something he finds repulsive and come to despise her. In the realm of medicine, a son is permitted to perform a procedure that draws his father's blood, because the underlying intention is purely to heal and do good [תורה תמימה].
Regarding the scope of this obligation, most commentators agree that it applies to upright individuals. Conversely, it is permissible, and even commanded, to despise entirely wicked people who actively destroy the divine purpose of the world [רשב״ם, אור החיים]. Yet, this love is not confined only to the Israelites. It explicitly extends to the convert and ultimately encompasses every human being created in the divine image [ביאור יש״ר, אם למקרא].
The ethical instruction concludes with a reminder of God's presence, which serves two crucial purposes. First, unlike physical actions that are visible to everyone, bearing a grudge is a secret kept entirely within the heart. The reminder serves to emphasize that God examines the deepest conscience and knows what is hidden within [שפתי כהן, ביאור שטיינזלץ]. Second, it elevates the love of others from mere social etiquette or human utilitarianism into a profound religious duty. God is the shared Father of all humanity; when people love His creations, they are directly honoring and loving the Creator Himself [אבן עזרא, חתם סופר, רש״ר הירש].