Ezekiel 25:12
Thus saith the Lord GOD; Because that Edom hath dealt against the house of Judah by taking vengeance, and hath greatly offended, and revenged himself upon them; Thus saith the Lord GOD; Because that Edom hath dealt against the house of Judah by taking vengeance, and hath greatly offended, and revenged himself upon them;
Ezekiel 25:12 stands within a group of prophecies directed against the foreign nations surrounding Judah. Those surrounding nations are presented together because they had rejoiced at Judah's humiliation and at the desolation of God's sanctuary. The chapter in which the verse stands points out the specific destruction that the Lord would bring upon each of those nations for that attitude.
The verse itself declares the Lord's judgment upon Edom because Edom dealt against the house of Judah by taking vengeance and in so doing greatly offended. Edom is thus named among the rejoicing nations specifically for revenging itself upon Judah. That vengeful dealing brought God's judgment upon Edom, a judgment that included the cutting off of its people and its animals.
The condemnation of Edom for taking vengeance on Judah and greatly offending is associated with Nebuchadnezzar's campaign that brought Idumea, Moab, and Ammon into submission after they had joined the final Jewish revolt. The fulfillment of this prophecy against the other nations is evident today. The same wrong warns against nursing resentment or seeking revenge for a real or imagined injury in connection with God's work.