Ver. 17. Neither shall he multiply wives to himself— He shall not indulge himself in a vast number of wives and concubines, especially women of different nations and religions, after the manner of the eastern monarchs. The reason is added, that his heart turn not away; i.e. lest his thoughts be diverted from minding the good of his people; and lest he be seduced from the true religion by marrying the worshippers of strange gods, as was the case with Solomon.
Neither shall he greatly multiply to himself silver and gold— He shall not set himself to heap up treasure in his own coffers for his private interest, which could not be done without great oppression of his subjects. Add to this, that luxury, and dissolution of manners, are the common effects of exorbitant wealth; vices most destructive to the people in general, who are too apt to imitate the example of their prince. Of this we have many instances in history, particularly in the kings of Persia, who, by their overgrown wealth, entailed ruin both on themselves and their whole people. Another fatal effect of immoderate wealth is, that it begets pride and tyranny; it being the epidemic folly of mankind to trust in their riches, and upon account thereof to form an over-weening opinion of themselves, and to behave with insolence and cruelty towards others.