to be so easy to see and understand that you do not need to say anything else about it/them :
Her success speaks for itself.
to be so easy to see and understand that you do not need to say anything else about it/them :
Her success speaks for itself.
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005