How does the author use foreshadowing in Out of the Silent Planet?

Chapter 21 ends the tale of Ransom's journey and introduces a new mystery. Before saying farewell, Oyarsa hints that he and Ransom may meet again. Knowing what he now knows about the history of Earth and Malacandra, Ransom gains a new point of view on ancient Earth mythology, which he thinks may contain more truth than most people believe. This foreshadows the concluding chapters of the book, which strengthen this connection.