A severe divine decree is sealed with an oath against the nation of Edom. God promises a strict measure-for-measure punishment that revolves entirely around the motif of blood. To confirm the absolute certainty of this judgment, God issues a solemn oath [מלבי"ם, ביאור שטיינזלץ].
The judgment destines Edom to fall by the sword, leaving their land filled with the blood of the dead [רש"י, מצודת דוד, רד"ק]. This violent end is a direct consequence of the massive amount of Israelite blood they previously spilled. The punishment is also deeply tied to their very identity, as the name Edom is rooted in the Hebrew word for blood [אברבנאל, מלבי"ם].
When destruction comes, the enemies attacking Edom will have no interest in taking captives or gathering loot. Their sole purpose will be pure bloodshed [מלבי"ם]. Other commentators explain that ruthless murderers will be the ones hunting them down [מצודת דוד, רד"ק], while an additional perspective suggests that the very blood of the victims Edom murdered will act as a relentless force pursuing them [ביאור שטיינזלץ].
The tragedy of Edom's fate carries a deep irony regarding their relationship with blood. The primary approach among commentators is that Edom, like any human society, feared murderers and hated the thought of their own blood being spilled. Because they despised and desperately tried to protect themselves from killers, those exact violent forces will now overtake them. Another view suggests this was a profound, essential hatred of blood that did not stem from a simple calculation of benefit or harm, and for this, they receive an exact measure-for-measure retribution [מלבי"ם].
Beyond physical fear, commentators identify other forms of blood that Edom despised. Some explain that the blood they hated was actually their brother, Jacob, who was their own flesh and blood [רש"י, חומת אנך, ביאור שטיינזלץ]. Others see this as a rejection of spiritual commandments. Edom hated the blood of circumcision [חומת אנך, אברבנאל]. Furthermore, they despised the spiritual birthright because they wanted to avoid getting dirty with the blood of animal sacrifices in the service of God. Because they rejected the sacred blood of worship, their punishment is to be soiled by the blood of the dead [רש"י, חומת אנך, אברבנאל]. Ultimately, had Edom not harbored such deep hatred toward these aspects of blood, violent bloodshed would not be hunting them down now [ביאור שטיינזלץ].