רַעְיוֹן

I applied my heart to know wisdom, and to know madness and folly. I perceived that this also was a chasing after wind.

For what does a man have of all his labor and of the striving of his heart, in which he labors under the sun?

There was no end of all the people, even of all them over whom he was—yet those who come after shall not rejoice in him. Surely this also is vanity and a chasing after wind.