The obligation of fasting is mandatory on a person who has fulfilled these requirements: He or she must be a Muslim, sane, must have reached puberty, must be healthy, and not in a state of travel; and for women, they must be in a state of purity (clean from menstruation and post childbirth bleeding). If a person fulfills the above prerequisites, fasting becomes valid and mandatory. Inferring from this definition, if one of these conditions is missing, the fast will be invalid. Indeed, it may be better to analyze each category of the definition.
Non-Muslim (Kafir)
Fasting is not obligatory on a non-Muslim because he is not commanded to fast and even if he decides to fast and follows all the regulations, it will not be accepted by Allah (SWT). If he or she wants to fast the Islamic fast, he has to declare the Kalimah first, and only then will the fast be accepted. Similarly, the non-Muslim (Kafir) is not obligated to perform any Islamic duties. If he converts to Islam during the month of Ramadan, for instance, in the middle of the month, it becomes incumbent upon him to fast the remaining days. There will be no making up the days he missed before becoming Muslim. Allah (SWT) states:
“Say to the unbelievers, if they desist from unbelief, their past would be forgiven of them...” (Al-Qur'an 8:38)
If one converts to Islam during the daytime in Ramadan, say 10:00 a.m. in the morning, he or she should observe the rest of the day in fasting. That is, from 10:00 a.m. until sunset, he should not break his fast.
Insane (Majnun)
The insane or retarded person is not obligated to keep his fast because he is deprived of sanity, a key component on which religious duties depend. In a hadith related by Ali Bin Abi Talib (raa), the Messenger of Allah (saas) said:
“The Pen that records the deeds has been lifted from three people; the insane person, until he recovers; the sleeping person, until he wakes up; and the minor, until he dreams (i.e., has wet dreams.)” (Ahmed)
This hadith indicates the fast of the insane person, for instance, is not valid because he cannot comprehend the worship, and he cannot meaningfully declare intention (niyyah), without which the acts are invalid. If he has mental relapses whereby he is healthy, and then on occasion is sick, the fast is mandatory upon him during the days and times he is healthy but not when he is unhealthy.
If he intends to fast in the morning, and he falls ill during this time, his fast is good as if he fainted as a result of illness, because he knows that he may experience an attack at certain times. If he gets well during the daytime in Ramadan, he should observe the fast the rest of the day because he is obligated to fast. However, he does not have to make up the day because his case is like that of unbeliever who becomes Muslim time or a minor he reached puberty during the day.
Minor (Sabiyy)
Similarly, the minor person is not obligated to observe fast (Sawm), because of the previous hadith related by Ali bin Abi Talib,
“... And the minor until he dreams.”
However, it is imperative that the parents or the guardians of the juveniles or adolescents encourage and urge them to fast so they will get used to it. It will be vital training for them in their worship, because they will not have any chance for training as soon as they reach puberty.
In a hadith reported by Rubayyiah Bint Mau'awwidh (raa), the Prophet (saas) sent a messenger to the village of Ansar on the morning of Ashura to inform them:
“Whoever wakes in fasting should continue his fasting, whoever wakes up without fasting should complete his day in fasting. So we used to fast, let our young children fast, and go to the Masjid with them. When one of the children cried for food, we would make toys from wool and give them to the children until it was time to break the fast.” (Bukhari and Muslim)
Non-Muslim (Kafir)
Fasting is not obligatory on a non-Muslim because he is not commanded to fast and even if he decides to fast and follows all the regulations, it will not be accepted by Allah (SWT). If he or she wants to fast the Islamic fast, he has to declare the Kalimah first, and only then will the fast be accepted. Similarly, the non-Muslim (Kafir) is not obligated to perform any Islamic duties. If he converts to Islam during the month of Ramadan, for instance, in the middle of the month, it becomes incumbent upon him to fast the remaining days. There will be no making up the days he missed before becoming Muslim. Allah (SWT) states:
“Say to the unbelievers, if they desist from unbelief, their past would be forgiven of them...” (Al-Qur'an 8:38)
If one converts to Islam during the daytime in Ramadan, say 10:00 a.m. in the morning, he or she should observe the rest of the day in fasting. That is, from 10:00 a.m. until sunset, he should not break his fast.
Insane (Majnun)
The insane or retarded person is not obligated to keep his fast because he is deprived of sanity, a key component on which religious duties depend. In a hadith related by Ali Bin Abi Talib (raa), the Messenger of Allah (saas) said:
“The Pen that records the deeds has been lifted from three people; the insane person, until he recovers; the sleeping person, until he wakes up; and the minor, until he dreams (i.e., has wet dreams.)” (Ahmed)
This hadith indicates the fast of the insane person, for instance, is not valid because he cannot comprehend the worship, and he cannot meaningfully declare intention (niyyah), without which the acts are invalid. If he has mental relapses whereby he is healthy, and then on occasion is sick, the fast is mandatory upon him during the days and times he is healthy but not when he is unhealthy.
If he intends to fast in the morning, and he falls ill during this time, his fast is good as if he fainted as a result of illness, because he knows that he may experience an attack at certain times. If he gets well during the daytime in Ramadan, he should observe the fast the rest of the day because he is obligated to fast. However, he does not have to make up the day because his case is like that of unbeliever who becomes Muslim time or a minor he reached puberty during the day.
Minor (Sabiyy)
Similarly, the minor person is not obligated to observe fast (Sawm), because of the previous hadith related by Ali bin Abi Talib,
“... And the minor until he dreams.”
However, it is imperative that the parents or the guardians of the juveniles or adolescents encourage and urge them to fast so they will get used to it. It will be vital training for them in their worship, because they will not have any chance for training as soon as they reach puberty.
In a hadith reported by Rubayyiah Bint Mau'awwidh (raa), the Prophet (saas) sent a messenger to the village of Ansar on the morning of Ashura to inform them:
“Whoever wakes in fasting should continue his fasting, whoever wakes up without fasting should complete his day in fasting. So we used to fast, let our young children fast, and go to the Masjid with them. When one of the children cried for food, we would make toys from wool and give them to the children until it was time to break the fast.” (Bukhari and Muslim)
