The Adventures of Tom Sawyer

Sid busted Tom when he played hookey by pointing out that he'd mended his lapels with a different colored thread. From the text above, we can infer that Tom plans to teach Sid a lesson for tattling.

“Why, I did sew it with white! Tom!”
But Tom did not wait for the rest. As he went out at the door he said:
“Siddy, I’ll lick you for that.”
In a safe place Tom examined two large needles which were thrust into the lapels of his jacket, and had thread bound about them—one needle carried white thread and the other black. He said:
“She’d never noticed if it hadn’t been for Sid. Confound it! sometimes she sews it with white, and sometimes she sews it with black. I wish to gee-miny she’d stick to one or t’other—I can’t keep the run of ‘em. But I bet you I’ll lam Sid for that. I’ll learn him!”