Ecclesiastes 2:17-20

17Therefore I hated life because the work that was done under the sun was distressing to me, for all is vanity and grasping for the wind.

18Then I hated all my labor in which I had toiled under the sun, because I must leave it to the man who will come after me.

19And who knows whether he will be wise or a fool? Yet he will rule over all my labor in which I toiled and in which I have shown myself wise under the sun. This also is vanity.

20Therefore I turned my heart and despaired of all the labor in which I had toiled under the sun.