Fasting is divinely ordained practice down the ages, it is prescribed for Muslims, as it was prescribed for pre-Islamic Ummah. The ardent practice is fundamentally meant for imbibing the spirit of self-restraint.
‘’O ye who believe! Fasting is prescribed to you as it was prescribed to those before you, that ye may (learn) self-restraint’’ (2:183)
Self-restraint or call it self-control is a pre-requisite both for steadfastness and fortitude. Put differently, it could mean in case of conflict between physical drives and lofty human values, one should eschew physical drives and abide by values. Furthermore, it is meant to condition a person to hard and laborious life, instead of getting conditioned to ease and laze.
It was with the idea of imbibing self-restraint that fasting was prescribed for pre-Islamic Ummahs, as it was prescribed for Muslim. There might have been though a different regimen, with a different set of do’s and don’ts down the ages, for pre-Islamic Ummahs. On who has to take the spiritual exercise and who may not is based on a set of conditions, wherein an exemption is granted for specially circumstanced, as ordained in the Holy Verse following the one noted above:
‘’ (Fasting) for a fixed number of days, but if anyone of you is ill or on a journey, the prescribed number (should be made up) from days later. For those who can do it (with hardship), is a ransom, the feeding of one that is indigent. But he that will give more, of his own free will, it is better for him. And it is better for you that ye fast, if only you know’’ (2:184).
Those who can do it with hardship include aged people or specially circumstanced. They are however obliged to feed one in need. Some jurists believe that specially circumstanced include women who are expecting or the ones nursing a baby, however some opine that they need to make it up later. Those who might be ill or travelling need to make up the days they didn’t fast, later.