Ecclesiastes 2:11
Then I looked on all the works that my hands had worked, and on the labor that I had labored to do: and, behold, all was vanity and vexation of spirit, and there was no profit under the sun.
Nave's Topical Index—AKJV

Ecclesiastes 4:4
Again, I considered all travail, and every right work, that for this a man is envied of his neighbor. This is also vanity and vexation of spirit.
Nave's Topical Index—AKJV