John Wesley on Isaiah 34:5

Bathed - In the blood of these people. Heaven - Where God dwells; in which this is said to be done, because it was there decreed and appointed. Idumea - Upon the Edomites, who, tho' they were nearly related to the Israelites, yet were their implacable enemies. But these are named for all the enemies of God's church, of whom they were an eminent type. The people - Whom I have cursed, and devoted to utter destruction, as the word properly signifies.