a metaphor is a figure of speech that consists in making a direct comparison between elements that aren't obviously related, in order to create an image in the reader's mind. The given lines from Martin Luther King Jr.'s Nobel Peace Prize acceptance speech we can see an example of a metaphor that compares justice with a wounded person, this metaphor helps to make the speech more poetic.
I am a concerned citizen of this country. And I am very worried our incessant and over use of natural resources causing natural disasters. That is why I am writing this letter to be published by you in the esteemed columns of your widely circulated daily to create a general awareness.