Ecclesiastes 2:18-20

¹⁸And I hated all my labor wherein I labored under the sun, seeing that I must leave it unto the man that shall be after me.

¹⁹And who knoweth whether he will be a wise man or a fool? yet will he have rule over all my labor wherein I have labored, and wherein I have showed myself wise under the sun. This also is vanity.

²⁰Therefore I turned about to cause my heart to despair concerning all the labor wherein I had labored under the sun.