A powerful declaration of divine justice unfolds, rooted in the strict principle of measure for measure. God swears to punish the nation of Edom with the identical intensity and scope they used when attacking the Israelites. The primary approach among commentators is that this guarantees a precise and proportional punishment. The exact anger and vengeance Edom displayed will be turned back on them, with their jealousy representing a deep, intense fury [מצודת ציון].
The underlying motive for this violence is closely examined. Edom directed their harm at the Israelites purely out of a deep, relentless hatred [מלבי"ם, ביאור שטיינזלץ]. Because of this, Edom cannot defend their cruelty by claiming the Israelites were simply receiving a deserved punishment for their own sins. They did not act to serve divine justice, but rather out of sheer malice. Consequently, they will face a penalty that perfectly matches their own cruelty [אברבנאל].
Ultimately, this severe judgment serves a much larger purpose. By bringing justice upon Edom, God ensures that His might and careful providence will be clearly recognized by the Israelites, inspiring them to trust in His power [רש"י, מצודת דוד, ביאור שטיינזלץ, אברבנאל]. Beyond witnessing His strength, this judgment will serve as absolute proof to the Israelites that God has chosen them as His people. At the exact moment He strikes down their enemies, He will reveal Himself to the Israelites to bring them goodness and blessing [רד"ק].