A framing device is narrative technique in which a work’s main story occurs inside an unrelated, separate narrative. “Rip Van Winkle” is a Russian nesting doll of framing devices. The outermost framing narrative is Geoffrey Crayon, the ostensible collection of all the stories in Irving’s book describing how he found the papers of another fictional character, Diedrich Knickerbocker. This kicks off the second framing device, as Knickerbocker, in turn, explains how he recorded Rip’s story. Finally, Rip’s own story, the main narrative, takes place.

The effect of these many framing devices is to create the effect of hearsay and folklore. We are far from the tale’s original source, learning of the events third-hand (or fourth-hand, if Irving himself counts as another re-teller). Paradoxically, the framing device is making fun of official, historical works which cite sources citing sources citing sources. 

An epigraph is a quotation from another work that an author includes at the opening of his or her own story to provide context or introduce a major theme. Epigraphs carry a sense of the epic, so by including one, Irving is satirically implying that his little story is a hugely important work of literature.