intake of food that they can practice their devotions and perform deeds of virtue and struggle in their lives according to the dictates of Divine law.
There comes a time in the life of one who has purified his soul and attained the proximity of Allah when he has the ability to withstand hunger not only for short periods but also for unusual intervals. This contention undoubtedly sounds absurd in the language of science and experiment, but the experts of Islamic esotericism believe that when the spirit of man strengthens, such phenomena are feasible. Avicenna (Ibn Sina), the great Shi'te philosopher, who is also known as Sayyid al-'Uqala' (the doyen of intellectuals) in his monumental "Ishlirat wa al-Tanbihat" says:

If you come to know that a Gnostic ('arif) has refrained for an unusual interval from receiving the little food he has, graciously assent and consider this among the well-known principles of nature.39

Therefore hunger for those who are not deprived of sustenance and are able to withstand the same is highly recommended due to the reasons mentioned above.

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39 Shaykh al-Ra'is Ibn Sina, al-Isharat wa ' I-Tanbihat, v.4, p.111