He who loves money is never satisfied by money, and he who loves wealth is never satisfied by income. This too is futile.
Solomon had shown the vanity of pleasure, gaiety, and fine works, of honour, power, and royal dignity; and there is many a covetous worldling that will agree with him, and speak as slightly as he does of these things; but money, he thinks, is a substantial thing, and if he can but have enough of that he is happy.
Commenting on Ecclesiastes 5:9-17
He that loveth silver shall not be satisfied with silver,.... The tillage of the earth is necessary, a very laudable and useful employment, and men do well to busy themselves in it; without this, neither the common people nor the greatest personages can be supplied with the necessaries of life; but then an immoderate love of money is criminal, which is here meant by loving...
Not only will God punish at last, but meanwhile the oppressive gainers of "silver" find no solid "satisfaction" in it. shall not be satisfied--so the oppressor "eateth his own flesh" (see on Ecc 4:1 and Ecc 4:5). with increase--is not satisfied with the gain that he makes.