Answer:
The frequent repetition of the same phrase, again and again, to focus on a distinct point, is termed to be epimone. In the above excerpt, Brutus uses epimone by saying 'for him have I offended.' He repeats the phrase when he gave his speech before the people of Rome after killing Ceasar. He wanted to disclose his feelings and his objective of killing Caesar and by using the epimone he wanted to prove himself and his dead to be good before the public of Rome.