Warning! My quote for the day includes mild spoilers:
When Obi-Wan moved to follow, Yoda's gimer stick barred his way. "A moment, Master Kenobi. In your solitude on Tatooine, training I have for you. I and my new Master."
Obi-Wan blinked. "Your new Master?"
"Yes." Yoda smiled up at him. "And your old one..."
from the novel Star Wars: Revenge of the Sith by Matthew Stowe