This is the classic, and probably most famous, scene from Tom Sawyer.
After being busted for playing hookey, Tom is forced to white-wash the fence on Saturday instead of having the whole day free, like his friends do. After trying, and failing, to get Jim to help him in return for a look at his sore toe, he gets a new idea. When Ben Rodgers comes, Tom is happily painting the fence. When Ben tries to tease Tom, but can't elicit a response, he asks why Tom is so happy. Tom answers "Why, It ain't everyday a body gets to paint a fence!" He uses human nature (namely what is optional is fun, what is mandatory is work) to not only get his friends to paint for him, but pay for the privilege. Some of the payment he gets are a dead rat, and marbles.