Imam Rabbani on Moderation
Question: In the great tariqat of Naqshibandiyye, following sunna is the main principle. The great Prophet (peace and blessings upon him) endured incredible self-mortification and pain. But in this tariqat, such things are forbidden; in fact, it is said that such things are harmful because they may produce visions and clairvoyance. Isn't it surprising to think that following sunna can be harmful?
Answer: My dear brother! Where have you heard that self-mortification is harmful in this path? In this path, the principle is to maintain our relation to God; to follow the beautiful sunna; to conceal one's spiritual states; to be moderate in eating, drinking, and clothing in short, every aspect of life. All these are intense self-mortifications and serious struggles with the nafs (the lower self).
Ignorant people don't view these as self-mortification and struggle. According to them, self-mortification is only to starve, and they see starvation as very valuable because those who live like animals place much importance on eating and drinking. Therefore, not eating and drinking seems as a very difficult struggle. They never value the continuous preservation of the relation to God, following the sunna and the like. They don't see not doing so as an ugly act...
It is clear that the masters of the path must conceal their spiritual states and avoid the self-mortification that the ignorant admire. The Prophet of Allah (peace and blessings upon him) said: "It is a great vice for anyone to attract notice in either the matters of this world or of religion.. Only the one whom Allah protects can be saved from this."
...Long periods of starvation are easier to endure than sustained moderation in eating and drinking. In fact, starvation can be very easily accomplished!
from Serving the Guest: A Sufi Cookbook