I maintain that the Ewells started it all, but Jem, who was four years my senior, said it started long before that. He said it began the summer Dill came to us, when Dill first gave us the idea of making Boo Radley come out.
– Harper Lee
To Kill a Mockingbird, Chapter 1. Scout is talking about her brother Jem’s broken arm, referred to in the opening lines of the novel. This foreshadows Bob Ewell’s heinous attack on the children.