Ecclesiastes 2:18-23 New Revised Standard Version (NRSV)
18 I hated all my toil in which I had toiled under the sun, seeing that I must leave it to those who come after me 19 —and who knows whether they will be wise or foolish? Yet they will be master of all for which I toiled and used my wisdom under the sun. This also is vanity. 20 So I turned and gave my heart up to despair concerning all the toil of my labors under the sun, 21 because sometimes one who has toiled with wisdom and knowledge and skill must leave all to be enjoyed by another who did not toil for it. This also is vanity and a great evil. 22 What do mortals get from all the toil and strain with which they toil under the sun? 23 For all their days are full of pain, and their work is a vexation; even at night their minds do not rest. This also is vanity.