Both individually and communally, fasting is typically a religious exercise—employed by devotees as means of supplication to the will of God, preparation for rites of devotion, worship of divinity, purification of the body so that spiritual issues can be better comprehended, penitence for transgressions against religious codes, and mourning for deceased persons. Underlying all these functions of fasting is a desire to create appropriate psycho-physical conditions, often ascetic ones, that facilitate a nexus between the practitioner and his or her deity, thereby enhancing spiritual needs while curtailing corporeal desires. Many fasts among Persians and other peoples occur during daylight hours, to test participants’ commitment to the endeavor at an active time. Success in surmounting the physical hardships imposed by a fast, and the spiritual benefits believed to have been accrued through this rite, frequently are celebrated through a festival at the culmination of the fasting period.

In Zoroastrianismor Mazdaism, however, fasting has been implicitly rejected throughout the faith’s history. Zoroastrian doctrine perceives no disjunction between spirit and matter along lines of good and evil; rather, it regards both as essential for achieving piety and both as susceptible to unrighteousness. Hence, Zoroastrians believe that the body should function as a means by which the soul can fight evil and regard any action that physically weakens the body as sinful. Moreover, sex is viewed as essential for procreation which brings more believers into the world. Standard or Young Avestan texts such as the Vidēvdād (Avesta, ed. Geldner, 3.33, 4.48, 7.70) emphasized that eating was essential for life, claimed consumption of meat enhanced spiritual perception, and suggested hunger and thirst caused much suffering. Pahlavi commentaries continued this anti-ascetic theme, stressing the notion of moderation or paymān between gluttony and privation in partaking of food, drink, and sex. Piety was said to result from not fretting about moderate consumption, and deviation from this mean was equated with concupiscence (Dēnkard, ed. Madan, pp. 267, 295). Given the Zoroastrian dislike for abstinence, it is likely that the Pahlavi term rōzag “the day of fast, fasting” derives from its Manichaean Middle Persian counterpart. Although a few Parsis in India have now assimilated from Hindus the notion of fasting as a means of expressing grief over death, most contemporary Zoroastrians still abhor this practice as enfeebling the body and thus reducing the soul’s ability to combat evil (Mistree, p. 19). One high priest or dastūr recently even went so far as to counsel laity that the only permissible fast is that of abstaining from sin (Dhalla, p. 187).

In Manicheism, fasting was probably introduced by Mani himself. While there is considerable evidence of the Manichean fasts (surveyed in Henning, pp. 146-64), exact details remain sketchy. Manichean doctrine proposed that a portion of the spirit or light of Zurvan, the father of greatness or high god, had become trapped in matter created by Ahriman the source of evil and corporeality. Fasting served as a means of limiting the transfer of this good, but entrapped, spirit through a series of evil corporeal incarnations. An important tenet, that pertaining to the so-called seal (Manichean Middle Persian muhr) of the mouth, urged strict control over consumption. The clergy (the elect) or dēndārān (bearers of religion) were required to abstain from consuming meat at all times and from any type of sexual activity. They also were expected to fast on Mondays. In general, Manichean clerics fasted during the daylight hours, eating one meal of vegetables and fruits after sunset. The laity or niyōšāgān (hearers) fasted each Sunday until sunset. Unlike clerics, they could eat meat (believed to contain much trapped spirit), although this practice was discouraged. Five (sometimes perhaps seven) fasts of two-day durations were observed by the community each year; these particular fasts seem to have been correlated with yimki or prayer periods. The most important communal fast took place during the thirty days preceding the vernal equinox, and culminated in the Bēma festival with confession of sins. This prolonged daytime fast included the fourth and fifth yimki, with the final prayer period commemorating Mani’s demise while in the custody of Sasanian authorities (Boyce, p.12).

In Babism/Bahaism, fasting developed from Muslim observances. The Bāb’s stipulations required fasting during the month of ʿAlā (sunset 1 March to sunset 20 March). Devotees between the ages of eleven and forty-two years were expected to abstain from all food, liquid, and sex between dawn and dusk, focusing instead on the divine. Children were supposed to fast from dawn until noon for the first eleven days only, an acknowledgment of the arduousness of the task (Walbridge, pp. 69-70). Bahāʾ-Allāh modified these stipulations, extending the fast to everyone between fifteen and seventy years old, while providing exemptions for pregnant, breast feeding, and menstruating women, and for men and women who are ill or required to engage in manual labor or need to travel for at least two hours on foot or at least nine hours via transportation during the period of the fast (al-Ketāb al-aqdas, paragraph 10). Smoking is also banned during the fast, as it is deemed to be an act of consumption. The Baha’i fast concludes just before the vernal equinox that marks the Persian new year festival or Nowrūz on 21March. This fast is regarded as a spiritual obligation necessary for expunging sin. Its efficacy is considered valid only if the rite has been dedicated to God, and then performed with true devotion and recitation of prescribed prayers (Walbridge, pp. 46, 58, 70-71).