Spiritual master can chastise his disciple

Satsvarupa Dasa Goswami: A devotee wrote him a letter saying, you are doubting my business project and so I am not enthusiastic and I am beginning to doubt you. Prabhupada said, "I do not doubt you as a sincere devotee, but I doubt your business capacity as no money is coming in. I am a layman. I don't know the jewelry business, but if I doubt it, what is my fault? Besides, the spiritual master can say to his disciple: You are useless, you are stupid, you are a fool. That is all right. Not that he has to flatter the disciple."