Eclesiastes - Capítulo 4, Versículo 8
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.