The Divine Nature
Commenting on the words in the Rosh Hashana hymn :His garment is charity; His mantle is wrath; He is girded with vengeance: His hidden character is compassion," the Rozdoler Rabbi said: "The author expalins in these words the Divine Nature. Only outwardly is our Lord clothed with wrath and girded with vengenance; but hidden within, He wears the garment of charity and compassion."
Source: Esser Kedushoth