How does the author use foreshadowing in A Wizard of Earthsea?

Ged understands that the language of the bird and the water which foreshadows his later understanding as the world as a word.

Ged understood the singing of the bird, and the language of the water falling in the basin of the fountain, and the shape of the clouds, and the beginning and end of the wind that stirred the leaves: it seemed to him that he himself was a word spoken by the sunlight.