Book of Ecclesiastes 1:2.2:21-23.
Vanity of vanities, says Qoheleth, vanity of vanities! All things are vanity!
For here is a man who has labored with wisdom and knowledge and skill, and to another, who has not labored over it, he must leave his property. This also is vanity and a great misfortune.
For what profit comes to a man from all the toil and anxiety of heart with which he has labored under the sun?
All his days sorrow and grief are his occupation; even at night his mind is not at rest. This also is vanity.