The transition from a life of wandering to the conquest of a promised homeland carries a profound spiritual danger: the illusion of self-righteousness. When a nation experiences supernatural military success and witnesses the downfall of its enemies, the natural human tendency is to interpret these events as proof of inherent moral superiority. Moses addresses this exact psychological trap. He warns the Israelites about the specific moment when God will push back, break, and eradicate the enemy nations [ספורנו, אוהב גר, שטיינזלץ] until they entirely disappear from sight [חזקוני]. In the flush of this triumph, the people are cautioned against believing that their successful entry into the land was earned through their own good deeds.
The primary approach among commentators is that Moses is negating a dual assumption. The people might mistakenly conclude that two factors combined to secure their victory: their own personal merit, making them more deserving than any other nation, alongside the sins of the Canaanites, which warranted expulsion. Moses clarifies that the triumph must not be attributed to this combination; rather, the wickedness of the nations alone, along with the ancient oath to the patriarchs, is the true cause [רש״י, רשב״ם, מלבי״ם, שפתי כהן, גור אריה]. Even if one acknowledges that the enemy is being punished for their sins, introducing personal merit into the equation remains strictly forbidden [אור החיים]. Alternatively, another perspective suggests that the wickedness of the nations is not part of the Israelites' mistaken assumption at all, but rather the stark truth being delivered by Moses. In this view, he tells the people not to attribute the inheritance of the land to their own righteousness, because the reality is that God is dispossessing the inhabitants solely due to their corruption [רמב״ן, שד״ל, הטור הארוך, אם למקרא, ביאור יש״ר, ברכת אשר].
Several factors could easily lead the Israelites into this trap of arrogance. Psychologically, watching enemies fall directly before one's eyes naturally breeds the feeling that such miracles are a personal reward [פני דוד]. Furthermore, the people might draw a flawed logical parallel: if the native nations are losing their homeland exclusively because of their evil, then the incoming nation must be gaining it exclusively because of its virtue [ביאור יש״ר]. The sheer speed of these supernatural victories could also create the illusion that God is rushing into battle as a reward for Israel's good deeds, when in truth, He acts swiftly due to the overwhelming wickedness of the enemy [ספורנו]. This highlights a sharp moral contrast: true righteousness reflects loyalty and commitment to God's laws, while wickedness represents arbitrariness and the violation of those laws [רש״ר הירש].
Shattering this illusion of self-righteousness is vital for the nation's survival. Overconfidence inevitably breeds spiritual complacency. If the Israelites were to believe the land was granted as an absolute, permanent reward for their virtue, they might assume God would never destroy their settlements, even if they later adopted the idolatrous practices of the Canaanites. By emphasizing that the current inhabitants are being expelled strictly for their wickedness, Moses instills a sobering realization: the Israelites themselves will face the exact same fate and lose the land if they choose to walk down that same corrupt path [העמק דבר, רלב״ג].
This stark denial of the people's righteousness raises a theological question, as elsewhere it is clear that God chose Israel out of love, and He loves the righteous. To resolve this, a distinction must be made between the nation of Israel as a historical whole, which is deeply loved and desired by God, and the specific generation standing before Moses. While that generation did possess the merit of following God into the barren desert, their frequent rebellions and continuous provocations over the course of forty years effectively nullified any claim to the personal righteousness required to earn the land [רמב״ן, מזרחי, שפתי חכמים, שפתי כהן].