Ecclesiastes 2:18-20

So I hated all the fruit (gain) of my labor for which I had labored under the sun, because I must leave it to the man who will succeed me. [Ps 49:10] And who knows whether he will be a wise man or a fool? Yet he will have control over all the fruit of my labor for which I have labored by acting wisely under the sun. This too is vanity (futility, self-conceit). So I turned aside and let my heart despair over all the fruit of my labor for which I had labored under the sun.