דברים, פרק כ״ג, פסוק י׳

Going out to war often triggers the shedding of societal constraints, blurring moral boundaries and unleashing unrestrained impulses. In a reality where individuals are detached from their normal routines and might easily succumb to cruelty and rage, an opposite standard is demanded: the battlefield is precisely where the highest level of purity, restraint, and self-control is required. The military campaign itself must be structured and organized, recognizing that a nation cannot rely on miracles alone but must employ proper military order [תורה תמימה, מלבי״ם]. Alternatively, this standard applies specifically to the small, elite frontline unit that carries the Ark of the Covenant into battle [אבן עזרא]. Furthermore, entering into warfare is morally restricted to situations of self-defense against an active, tangible enemy, strictly prohibiting unjustified wars of conquest [מלבי״ם, רש״ר הירש].

There are three primary reasons for the strict warning to avoid sin specifically during wartime. The primary approach among commentators focuses on human nature. Military camps naturally tend toward moral deterioration, robbery, violence, and promiscuity; thus, a special warning is necessary to maintain basic humanity and avoid adopting the corrupt customs of surrounding nations [רמב״ן, טור הארוך, רבנו בחיי, שטיינזלץ]. A second, more spiritual perspective explains that God walks within the camp to deliver Israel. His presence transforms the military encampment into a royal palace, demanding heightened holiness. This requires avoiding all impurity or disgusting elements, even prohibiting foods that might dull the soul [אבן עזרא, העמק דבר, אלשיך]. A third approach connects to the concept of strict justice. War is a time of acute physical danger, a moment when one's life hangs in the balance and is subjected to rigorous heavenly scrutiny. During such critical times, even the most minor infractions are examined, compelling soldiers to be meticulously careful regarding minor sins they might not normally guard against with such intensity during times of peace [רש״י, אור החיים, רא״ש].

The requirement to distance oneself from evil encompasses several layers of human behavior. On a basic level, it serves as a general warning against all forbidden acts, particularly the most severe sins that drive away the Divine Presence, such as idolatry, sexual immorality, and bloodshed [רמב״ן, תורה תמימה]. However, many commentators interpret the warning as a specific prohibition against foul language and slander. Gossip and slander within a military camp are considered even more dangerous than the external enemy, as they sow division, fragment the ranks, and ultimately lead to internal defeat. Furthermore, any malicious speech is, in essence, spoken directly into the ears of God, who dwells within the camp [ספרי, רמב״ן, בעל הטורים, העמק דבר, שפתי כהן].

Beyond speech, the standard of purity extends to one's thoughts. Soldiers face numerous temptations, and they are cautioned against looking at forbidden sights or entertaining sinful thoughts during the day. Such mental purity prevents nocturnal impurity, which would otherwise force the soldier to leave the holy camp [אור החיים, רבנו בחיי, משכיל לדוד]. On an allegorical level, the battlefield represents the perpetual spiritual struggle of the human experience. Going out to war symbolizes the internal fight against negative inclinations, which are a person's true enemies. To achieve victory in this lifelong campaign, an individual must guard against every negative thought or action, always remembering that God is present within their internal camp to assist in their spiritual battles [צרור המור, אלשיך].