Example of foreshadowing in To Kill a Mockingbird?

Atticus' warning to the children about killing mockingbirds, as well as Miss Maudie's confirmation of his words foreshadows Tom Robinson's unjust treatment by the town and court. Miss Maudie's comment also directly applies to the ridicule and gossip concerning Boo Radley.

"Shoot all the bluejays you want, if you can hit 'em, but remember it's a sin to kill a mockingbird."

"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."