Ecclesiastes 4:4, 8

Then I saw all labor and every skilful work, that for this a man is envied of his neighbor. This also is vanity and a striving after wind.

There is one that is alone, and he hath not a second; yea, he hath neither son nor brother; yet is there no end of all his labor, neither are his eyes satisfied with riches. For whom then, saith he, do I labor, and deprive my soul of good? This also is vanity, yea, it is a sore travail.