It is difficult to imagine how the prophets and psalmists could possibly have expressed more strongly the personal character of the wrath of God. While disaster is regarded as the inevitable result of man's sin, it is so in the view of the Old Testament, not by some inexorable law of an impersonal Nature, but because a holy God wills to pour out the vials of His wrath upon those who commit sin. Indeed, it is largely because wrath is so fully personal in the Old Testament that mercy becomes so fully personal, for mercy is the action of the same God who was angry, allowing His wrath to be turned away. It should be noted that many passages place the wrath and the mercy of God on the same plane as personal activities, for example, 'He retaineth not his anger for ever, because he delighteth in mercy' (Mi. 7: 18), or, 'Thou hast forgiven the  iniquity of thy people, thou hast covered all their sin. Thou hast taken away all thy wrath: thou hast turned thyself from the fierceness of thine anger' (Ps, 85: 2f).  - Leon Morris, Apostolic Preaching of the Cross, p.153