'Toils' in the Bible

What profit is there to the worker from that in which he toils?

This also is a grievous evil—exactly as a man is born, thus will he die. So what is the advantage to him who toils for the wind?

Here is what I have seen to be good and fitting: to eat, to drink and enjoy oneself in all one’s labor in which he toils under the sun during the few years of his life which God has given him; for this is his reward.

So I commended pleasure, for there is nothing good for a man under the sun except to eat and to drink and to be merry, and this will stand by him in his toils throughout the days of his life which God has given him under the sun.