דברים, פרק כ״ז, פסוק י״ז

Stealing land through deceit strikes at the deepest foundations of human society and justice. This crime is considered exceptionally severe, equated to the rampant robbery that sealed the fate of the generation of the Flood, and it stands in absolute contradiction to the great principle of loving one's neighbor as oneself [מלבי״ם]. The primary approach among commentators is that this act involves secretly pushing a physical boundary marker backward into a neighbor's property, thereby enlarging one's own land and stealing from another [רש״י, מזרחי, גור אריה, ביאור שטיינזלץ].

The central element of this crime is concealment. Expanding one's property in this way is done craftily, relying on the assumption that the neighbor will not notice the slight change. If the theft were done openly, the victim would simply take the offender to court [בכור שור, ביאור שטיינזלץ]. This secretive character directly connects this act to the curse against misleading a blind person. In both situations, the victim is entirely unaware of who caused them harm [אבן עזרא, חזקוני].

This strict prohibition applies everywhere, not just within the borders of the Land of Israel [ברכת אשר על התורה], and the Patriarchs were exceedingly careful to avoid it throughout their lives [מלבי״ם]. Beyond the physical theft of real estate, the concept expands to include any secret and deceitful invasion into another person's private domain or area of authority [ביאור שטיינזלץ]. Furthermore, encroaching on a neighbor's boundary serves as a reference to the prohibition of taking another man's wife. Such an act is a profound invasion into a friend's domain, ultimately leading to the destruction of the family unit and resulting in children who do not know their true father [קיצור בעל הטורים].