This is guru. Guru means he'll always enlighten the disciples with the light of sastra. Not that he will say, "There is no need of sastra. I am incarnation. I, whatever I speak, you take it." No. This is rascal. You should immediately, who has no reference to the sastra, immediately take him as a rascal number one. This is the conclusion.

From Srila Prabhupada's lecture on Bhagavad-gita 1.24–25 — July 20, 1973