Ecclesiastes 2
21 Ref For there is a man whose labor is with wisdom, and with knowledge, and with skilfulness; yet to a man that hath not labored therein shall he leave it for his portion. This also is vanity and a great evil.
22 Ref For what hath a man of all his labor, and of the striving of his heart, wherein he laboreth under the sun?
23 Ref For all his days are `but' sorrows, and his travail is grief; yea, even in the night his heart taketh no rest. This also is vanity.