Ecclesiastes 4:4; Ecclesiastes 4:7-8
Then I saw that all toil and all skill in work come from one person's envy of another. This also is vanity and a chasing after wind.
Again, I saw vanity under the sun:
the case of solitary individuals, without sons or brothers; yet there is no end to all their toil, and their eyes are never satisfied with riches. "For whom am I toiling," they ask, "and depriving myself of pleasure?" This also is vanity and an unhappy business.