Although the wicked man surrounds himself with luxury and provides for himself the best of what the earth has to offer, he cannot maintain himself in this state when he lives in violation of God’s will. For a time he prospers, and though others around him may be going without, he makes sure that he lacks nothing.
‘As in all Scripture, when it is said that the wicked are fat, it is not meant simply that they are fat in their bodies, but that they take such a pride in the goods and riches that they are puffed up against God and full of poison and presumptuousness. Although they are lean in their bodies, they are ready to burst with another cursed fatness, in that they are puffed up against God’ (Calvin – English updated).
Gill offers various interpretations of verse 28. It describes the way such a man destroys the cities and palaces enjoyed by others, and out of their ruins builds ones to perpetuate his name for posterity. Or it expresses the sinful course of life of a man who lives in desolate places in order to do harm to others. Or, as in the KJV, it describes the punishment of the wicked man.