Ecclesiastes 2
20 Ref Therefore I began to cause my heart to despair concerning all the labor in which I had labored under the sun.
21 Ref For there is a man whose labor is with wisdom, with knowledge, and with skillfulness; yet he shall leave it for his portion to a man who has not labored for it. This also is vanity and a great evil.
22 Ref For what has a man of all his labor, and of the striving of his heart, in which he labors under the sun?
23 Ref For all his days are sorrows, and his travail is grief; yes, even in the night his heart takes no rest. This also is vanity.