Complete separation from the native inhabitants and their culture is an absolute requirement for protecting the spiritual identity of the Israelites. This final warning serves as the conclusion to the collection of laws known as the Book of the Covenant [אבן עזרא, קאסוטו]. A question naturally arises regarding the instruction forbidding these nations from living in the land, since the Israelites were already commanded to destroy the Canaanite nations. Commentators explain that this specific warning applies to situations where warfare is not an option. For instance, this could occur during times of peace [פענח רזא], or if the inhabitants surrendered and made peace before the Israelites entered the land. Under these circumstances, killing them is prohibited, yet it remains strictly forbidden to allow them to live in the land unless they accept the Seven Noahide Laws [תורה תמימה]. This prohibition applies specifically to areas the Israelites have already conquered and settled [ספורנו], and it remains in effect even if the native population is reduced to a small minority or lives as submissive residents [העמק דבר, מלבי״ם].
The primary concern is the grave danger of cultural influence. A person might feel spiritually strong enough to resist their surroundings, perhaps even hoping to reform the local inhabitants. However, the reality will be the exact opposite, as the locals will ultimately drag the Israelites down with them. Maintaining isolation from foreign influences is critical for shaping the newly formed world of the nation [רש״ר הירש, ביאור שטיינזלץ]. The severity of this danger is emphasized by the warning that these nations will cause the Israelites to sin directly against God. This highlights that the holiness of the Israelites depends entirely on their connection to Him, and idol worship strikes directly at this spiritual root, diminishing it [אור החיים].
There are different perspectives on how this spiritual downfall unfolds. The primary approach among commentators is that the warning serves as a direct statement of fact: allowing them to stay will inevitably result in the Israelites adopting their idol worship [רש״י]. Another perspective suggests a chain reaction, where allowing the nations to remain in the land becomes the initial trap. They will slowly tempt the Israelites, causing them to sin until they eventually worship foreign gods [רמב״ן]. Others suggest that the danger extends beyond literal idol worship to include general moral corruption and a decline in basic human ethics, such as the Noahide laws [הכתב והקבלה].
The ultimate trap can be understood in several ways. It might be the Canaanite nation itself [שד״ל], or the constant visual presence of idol worship, which cannot be kept around even for mere decoration or historical preservation [ביאור יש״ר, הכתב והקבלה]. Interestingly, the temptation to engage in idol worship does not always stem from a genuine belief in false gods. Instead, it can arise from a false hope that these practices bring physical benefits and reveal the future [אור החיים], or it might stem from a deep fear of the Canaanites and their perceived powers [העמק דבר]. The singular nature of this trap teaches a profound lesson about spiritual decline. It does not happen instantly. Rather, one offense leads to another. A seemingly small sin acts as a snare, gradually pulling a person downward until it results in complete and total idol worship [אלשיך].