"[In chapter four] of [Pilgrim's Progress] the story has now become fully established, and it is a universal pattern in travel stories from Honer's Odyssey and Spencer's Faire Queene to C.S. Lewis' Naria stories and Tolkein's Lord of the Rings. It consists of a predictable back-and-forth movement between journey along the path and temporary rest in a place, usually a house, palace or castle. The rituals of arrival at the beginning and taking leave at the end encircle the stay at the residence. The main actions are (a) refreshment and renewal for the weary traveler and (b) instruction for the traveler but equally for the reader. The latter feature means that the author's didactic purpose is fully evident in these interspersed interludes" (Ryken 29).
Ryken, Leland. Bunyan's The Pilgrim's Progress. Christian Guides to the Classics,