Ecclesiastes 2:20-23

²⁰And I turned round to cause my heart to despair concerning all the labour that I laboured at under the sun.

²¹For there is a man whose labour is in wisdom, and in knowledge, and in equity, and to a man who hath not laboured therein he giveth it — his portion! Even this is vanity and a great evil.

²²For what hath been to a man by all his labour, and by the thought of his heart that he laboured at under the sun?

²³For all his days are sorrows, and his travail sadness; even at night his heart hath not lain down; this also is vanity.