While traveling to his new home, Yoda converses with Obi-Wan Kenobi’s Force Ghost.
Kenobi would later order Luke to go to Dagobah while he was near death on Hoth, which we can all agree was poor timing.
The deceased Jedi Master asks that his green colleague train the “young Skywalker” in the ways of the Force, and Yoda at first believes that Kenobi is talking about Leia, who we know is a Skywalker by birth.
With her in mind, Yoda is all too willing to accept the role of instructor, but when Kenobi clarifies that he’s talking about Luke, Yoda is less than pleased with the farm boy from Tatooine being his student, but he nonetheless agrees to Kenobi’s request and gives permission to send Luke his way.