The word "oppression" can be translated with a verbal phrase. AT: "Because of the many things that people do to oppress others" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])
Here "arms" refers to power or strength. AT: "they call for someone to deliver them from the power of mighty men" (See: [[rc://en/ta/man/translate/figs-metonymy]])