Again I looked, and I considered all the oppression taking place under the sun. I saw the tears of the oppressed, and they had no comforter; the power lay in the hands of their oppressors, and there was no comforter.
Solomon had a large soul (Kg1 4:29) and it appeared by this, among other things, that he had a very tender concern for the miserable part of mankind and took cognizance of the afflictions of the afflicted. He had taken the oppressors to task (Ecc 3:16, Ecc 3:17) and put them in mind of the judgment to come, to be a curb to their insolence...
Commenting on Ecclesiastes 4:1-3
So I returned, and considered all the oppressions that are done under the sun,.... The wise man, according to Aben Ezra, returned from the thought, which he had expressed in the latter part of the preceding chapter, that it was good for a man to rejoice in his works, and called it in; since he could not rejoice, when he considered the oppression and violence...
So I returned, and considered all the oppressions that are done under the sun: and behold the tears of [such as were] oppressed, and they had no comforter; and on the side of their oppressors [there was] power; but they had no comforter. (a) He makes here another discourse with himself concerning the tyranny of them that oppressed the poor.