One language technique employed in this quote is the use of second person pronouns. By using the personal pronoun "you," the speaker is using direct language to make the quote personally relevant to his or her listener. The use of the pronoun "you" is different from "him" or "her" or "one" because it makes the meaning of the statement specifically important to the person listening.
Another language technique is alliteration, which is the repetition of the sound of beginning letters in words. The repetition of the "p" sound in "poor" and "person" emphasizes two very important words in the quote. The focus of the quote is in these two words, and the alliteration draws attention to the meaning of the words.
One last language technique is hyperbole, or literary exaggeration. The speaker of this quote uses the word "never" in a hyperbolic way to instruct the listener to treat insults casually so to feel less hurt by them. "Never" is a strong word to use in any situation, but in this case, its strength is intended to capture the attention of the listener.