Vengeance is whose?

“Based on these two images of God as king (sovereign) and warrior (victor over evil), several ethical conclusions follow, only one of which I will discuss. Christians need not—should not—engage in violence. The fact that Yahweh our God is a powerful warrior, whose passion for holiness and justice is intense and who will deal decisively with evil, means that his followers can afford to leave the righting of wrongs in God’s hand. Both testaments emphatically affirm this point. Moses asserts in the name of God, “Vengeance is mine” (Deut 32:35). Paul, in urging a peaceable lifestyle, tells his audience in Rome: “Never avenge yourselves, but leave room for the wrath of God, for it is written, ‘Vengeance is mine, I will repay, says the Lord’” (Rom 12:19). God is completely able to deal with the inequities and the violence in the world without our help.”—Martens, War in the Bible and Terrorism in the Twenty-First Century, page 55