'Oppression' in the Bible

Again, I observed all the acts of oppression being done under the sun. Look at the tears of those who are oppressed; they have no one to comfort them. Power is with those who oppress them; they have no one to comfort them.

If thou seest the oppression of the poor, and violent perverting of judgment and justice in a province, marvel not at the matter: for he that is higher than the highest regardeth; and there be higher than they.

Surely oppression maketh a wise man mad; and a gift destroyeth the heart.

For there is a proper time and procedure for every matter, for the oppression of the king is severe upon his victim.