Quran Lessons
70 Matters Related to Fasting
(36) If a person embarks on an obligatory fast, such as making up for a day missed in Ramadaan, or fulfilling a vow, or fasting as an act of expiation (kafaarah), he must complete the fast, and he is not permitted to break it unless he has a valid excuse for doing so. In the case of a naafil fast, "the person who is observing a voluntary fast has the choice either to complete the fast or to break it" (reported by Ahmad, 6/342) - even if there
is no reason to break it.
The Prophet (peace and blessings of Allah be upon
him) got up fasting one morning, then he ate. (As reported in Saheeh Muslim, in the story of the al-hais (a type of food) that was given to him as a gift when he was in 'Aa'ishah's house; (no. 1154, 'Abd al-Baaqi).
But will the person who breaks his fast for no reason be rewarded for the fasting that he has already done? Some of the scholars say that he will not be rewarded (al-Mawsoo'ah al-Fiqhiyyah, 28/13), so it is better for the person who is
observing a voluntary fast to complete it, unless there is an acceptable reason for not completing it.
(36) If a person does not know that Ramadaan has started until after dawn, he has to stop eating and drinking for the rest of the day, and he has to make that day up later on, according to the majority of scholars, because the Prophet (peace and
blessings of Allah be upon him) said: "There is no fasting for the one who does not have the intention to fast from the night before." (Reported by Abu Dawood, 2454).
(37) If a prisoner or captive knows that Ramadaan has begun by sighting the moon himself or by being told by a trustworthy person, he has to fast. If he does not know when the month is beginning, he must try to work it out for himself (ijtihaad) and act according what he thinks is most likely. If he later finds out that his fasting coincided with Ramadaan, this is fine
according to the majority of scholars, and if his fasting came after Ramadaan, this is fine according to the majority of fuqahaa', but if his fasting came before Ramadaan, this is not acceptable, and he has to make up the fast. If part of his fasting coincided with Ramadaan and part of it did not, what coincided with it or came after it is fine, but what came before
is not OK. If the matter never becomes clear to him, then his fasting is fine because he did the best he could, and Allah burdens not a person beyond his scope. (Al-Mawsoo'ah al-Fiqhiyyah, 28/84).