Here the word "hand" represents control. Alternate translation: "the control of the wicked ... the control of the ruthless" (See: [[rc://en/ta/man/jit/figs-metonymy]])
This nominal adjective refers to a person who is cruel and who does not care if he hurts other people. It is used here as a generic noun that refers to ruthless people in general, not one particular person. Alternate translation: "ruthless people" or "cruel people who will harm you" (See: [[rc://en/ta/man/jit/figs-nominaladj]] and [[rc://en/ta/man/jit/figs-genericnoun]])