How does the author use foreshadowing in The White Dragon?

The story begins with Jaxom and the description we get of Ruth. Ruth is the only white dragon there is, and he is also much smaller than the other dragons. Jaxom feels conflicted about the fact that he is too young to be Holder of Ruatha but also unable to fly with the other dragonriders because it is too dangerous for the only heir to Ruatha to be in battle against the Thread that fall from the sky.This foreshadows Jaxom teaching Ruth to flame and fight Thread.