John Gill, on Prov 10:15

The rich man's wealth is his strong city,.... What a fortified city is to persons in time of war, that is a rich man's wealth to him; by it he can defend himself from the injuries of others, and support himself and family in times of public calamity; for money is a defence, and answers all things, Ecc 7:12. Or his wealth is so in his own apprehension and conceit; he puts his trust and confidence in it, and thinks himself safe and secure by it; when he is trusting to uncertain riches, which will fail him; these may fly away from him in life, and leave him exposed to distress and danger; and, however, will not secure him at death from the wrath of God and everlasting destruction. Or he is lifted up with his riches, is in high spirits, and despises others; thinking himself safe, as in a strong castle, and fears nothing, distresses, diseases, or death; the destruction of the poor is their poverty: or their poverty is their consternation, as the word (h) signifies, it frightens them; they, knowing their circumstances, are afraid of everybody and of every thing; not being able to defend themselves against their enemies, or support themselves in times of public calamity, as war, famine, or pestilence. (h) "consternatio", Mercerus, Gejerus, Michaelis.