Ecclesiastes 2:21-23

21When there is a person whose work was done with wisdom, knowledge, and skill, and he must give his portion to a person who has not worked for it, this too is futile and a great wrong.

22For what does a person get with all his work and all his efforts that he labors at under the sun?

23For all his days are filled with grief, and his occupation is sorrowful; even at night, his mind does not rest. This too is futile.