What commentary is Hesse making by having the oldest Samana yell at Siddhartha?

In my opinion, Hesse is illustrating the capacity for learning that Siddhartha possesses. The elder scolds him for his desire to leave, based upon Siddhartha's declaration there's nothing left for him to learn. The elder disagrees, and Siddhartha hypnotizes him, proving that he's acquired a wealth of knowledge..... knowledge unknown even to the ancient one.