One thing is true: although the teacher cannot give the knowledge, he or she can kindle the light if the oil is in the lamp.
Bowl of Saki, September 20, by Hazrat Inayat Khan
Commentary by Pir-o-Murshid Inayat Khan:
"No one can give spiritual knowledge to another, for this is something that is within every heart. What the teacher can do is to kindle the light which is hidden in the heart of the disciple. If the light is not there, it is not the fault of the teacher. There is a verse by Hafiz in which he says, 'However great be the teacher, he is helpless with the one whose heart is closed.' ...
In the center of the emblem of the Sufis there is a heart; it is the sign that from the heart a stream rises, the stream of divine knowledge."
And so we are brought back inside. To look more deeply at how my heart is open, and how it is closed. The Teacher wants to help, but is my heart open?