Adam Clarke on Ecclesiastes 4:8

There is one alone, and there is not a second - Here covetousness and avarice are characterized. The man who is the center of his own existence; has neither wife, child, nor legal heir; and yet is as intent on getting money as if he had the largest family to provide for; nor does he only labor with intense application, but he even refuses himself the comforts of life out of his own gains! This is not only vanity, the excess of foolishness, but it is also sore travail.