Ezekiel 25:15
Thus saith the Lord GOD; Because the Philistines have dealt by revenge, and have taken vengeance with a despiteful heart, to destroy it for the old hatred; Thus saith the Lord GOD; Because the Philistines have dealt by revenge, and have taken vengeance with a despiteful heart, to destroy it for the old hatred;
Ezekiel 25:15 belongs to prophecies of judgment against the nations around Judah. The Hebrew word neh-phesh is here translated heart. Soul is used for a person's feelings or inner person, to which revenge and contempt can be attributed, and the Philistines took revenge with a heart filled with contempt and old hatred.
The Philistines took vengeance against Judah to destroy it out of old, longstanding hatred and a despiteful, spiteful heart. Because of that revenge and hatred the Lord pronounced judgment on them. He foretold specific destruction for those who rejoiced at Judah's humiliation.
That judgment would be the Lord executing great vengeance on them with furious rebukes. The verse warns against keeping old resentment over a real or imagined injury and taking vengeance against God's people.