What page on To Kill a Mockingbird does it mention the mockingbird?

It says it on the back of some books. It is on page 103.

He says "Shoot all the bluejays you want, if you can hit 'em, but remember it's a sin To Kill a Mockingbird."

My class thought of it like this...

Shoot all the Bob Ewells you want, if you can hit 'em, but remember it's a sin to kill a Tom Robinson.