Once upon a time, An ill patient was taken to a Sufi master, the Sufi master starts praying for the ill.

One person from the people that brought the patient says to the Sufi master, "How do you think saying words to this ill patient hill him?"
Sufis are people who don't talk but this time, the Sufi master turned to him and said: "You are such a fool who knows nothing".
This made the man extremely angry.
The Sufi master then turned to the man and said: "if my words can make you extremely angry, why cant it heal the sick?".