Is The Force Awakens novel introduction quote foreshadowing The Last Jedi plot?
"First comes the day
Then comes the night.
After the darkness
Shines through the light.
The difference, they say,
Is only made right
By the resolving of gray
Through refined Jedi sight."
- Journal of the Whills, 7:477
from The Force Awakens novel.
Here's a great fan interpretation: