Ecclesiastes 2:17-21

Therefore 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. Then 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. And 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. Therefore I turned my heart and despaired of all the labor in which I had toiled under the sun. For there is a man whose labor is with wisdom, knowledge, and skill; yet he must leave his heritage to a man who has not labored for it. This also is vanity and a great evil.