Translation
I have seen all this and devoted
Go to footnote numbermy inner being to every deed that is done under the sun. There is a time when a man has mastery
Go to footnote numberover another man
Go to footnote numberto his own hurt.
Paraphrase
I have seen all the things I have told you about. I have devoted my mind and soul to understanding every endeavor and every pursuit that is chosen by man here on earth. Here are a few more things I have found: There are times when a man of authority rules over the men under him in ways that hurt both them and himself, (but he does not see it until the damage has been done).
Footnotes
1
This word means “to give.” It also means “to bestow, to grant, to dedicate or devote.” How did Solomon devote his heart to everything? He devoted himself, starting with his inner being, to search out every matter, to investigate and grapple with every problem.
2
While he is on the topic of respect for authority, he has something to say about the use of authority. While the people who do not have much authority wish they had more, and may envy rulers with lots of authority, Solomon is letting them know that having authority over other people can be tricky, it can cloud your thinking, it can come back to bite you. We know this to be true especially of those that abuse their authority.
3: “another man”
The word “adam” is used twice in this sentence because “adam” means “man.” A literal rendition of the Hebrew would be something like this: “A time in which the adam has mastery over adam to his own hurt.” Notice the word “another” is not in the original but is added because it is implied that one man has mastery over another man.