what movie is thiswhat movi is this? i've only heard a clip of the audio, but it sounded like maybe an i.r.a.?

i've only heard a clip of the audio, but it sounded like maybe an
i.r.a. film. in the movie some guys ask another to teach them how to
fight. he replys, "i can't teach you how, because you already can".
and then he tells them "the only difference is i have the confidence
to fight". i would love to see this flick, so i'd appreciate any help.