Significant Quotes for 100 After you tell who said this line, describe when in the story it is said and how it is important to the story and the theme. Your father’s right. Mockingbirds don’t do one thing but make music for us to enjoy. They don’t eat up people’s gardens, don’t nest in corncribs, they don’t do one thing but sing their hearts out for us. That’s why it’s a sin to kill a mockingbird.