Answer:
This quote comes from Act 3, scene 1 of Romeo and Juliet, by Shakespeare. The speaker is Romeo to Tybalt.
In this scene, Tybalt comes to Hamlet to challenge him. Tybalt feels attacked by Romeo and the Montagues. He comes looking for Romeo with the intention of fighting. However, in response to Tybalt's violence, Romeo delivers this line. This line shows how Romeo chooses to be nonviolent in an attempt to calm the feud between the families.
The first part of the line explains how Romeo feels that he never hurt Tybalt, and thus there is no need to fight. In the last part of the line, Romeo says that Tybalt does not understand the reason Romeo loves him. This is an example of dramatic irony. Romeo and the audience know that Romeo loves Tybalt because Romeo is now family through the marriage between Juliet and Romeo.
This line is important because it shows how Romeo attempts to stop the violence. It also clearly shows the audience how keeping the marriage a secret is leading people to getting hurt. Additionally, during this scene, Mercutio is with Romeo and also does not know about the marriage. So, he believes that Romeo standing down is dishonorable and cowardly. Mercutio's anger and pride lead to him agreeing to fight Tybalt in Romeo's place. In the end, this fight is responsible for the deaths of both Tybalt and Mercutio.
Additionally, this line could be referenced to understand the theme of secrets. Throughout the play, both Romeo and Juliet keep foolish secrets from their families. By refusing to tell people of their secret marriage many people get hurt. So, this line represents how keeping secrets can often have negative, unintended consequences.