What is the profit to a man in all his labor which he labors under the sun?

Then I looked on all the works that my hands had done, and on the labor that I had labored to do; and, behold, all is vanity and vexation of spirit; and there is no profit under the sun.

What profit does he have who works in that in which he labors?

When the good thing increases, those who eat it increase; then what profit is it to its owners, except to see it with their eyes?

And this also is a sore evil, that in all, as he came, so shall he go; and what profit does he have who has labored for the wind?