Believers! Fasting is enjoined upon you, as it was enjoined upon those before you, that you become God fearing. Quran 2:183
¹Like most other injunctions of Islam those relating to fasting were revealed gradually. In the beginning the Prophet had instructed the Muslims to fast three days in every month, though this was not obligatory. When the injunction in the present verse was later revealed in 2 A.H., a degree of relaxation was introduced: it was stipulated that those who did not fast despite their capacity to endure it were obliged to feed one poor person as an expiation for each day of obligatory fasting missed (see verse 184). Another injunction was revealed later (see verse 185) and here the relaxation in respect of able-bodied persons was revoked. However, for the sick, the traveler, the pregnant, the breast-feeding women and the aged who could not endure fasting, the relaxation was retained. (See Bukhari, `Tafsir al-Qur'an', 25; Tirmidhi, 'Sawm', 21; Nasa'i, `Siyam', 51, 62, 64; Ibn Majah, `Siyam', 12; Ahmad b. Hanbal, Musnad, vol. 3, p. 104; vol. 4, pp. 347 and 418; vol. 5, p. 29 - Ed.)  
Fasting is for a fixed number of days, and if one of you be sick, or if one of you be on a journey, you will fast the same number of other days later on. For those who are capable of fasting (but still do not fast) there is a redemption: feeding a needy man for each day missed. Whoever, voluntarily, does more good than is required, will find it is better for him; ²This act of extra merit could either be feeding more than the one person required or both fasting and feeding the poor. and that you should fast is better for you, if you only know. ³Here ends the early injunction with regard to fasting which was revealed in 2 A.H. prior to the Battle of Badr. The verses that follow were revealed about one year later and are linked with the preceding verses since they deal with the same subject.  Quran 2:184

During the month of Ramadan the Qur'an was sent down as a guidance to the people with clear signs of the true guidance, and as the Criterion (between right and wrong). So those of you who live to see that month should fast it, and whoever is sick or on a journey should fast the same number of other days instead. Allah wants ease and not hardship for you so that you may complete the number of days required, ⁴Whether a person should or should not fast while on a journey is left to individual discretion. We find that among the Companions who accompanied the Prophet on journeys some fasted whereas others did not; none objected to the conduct of another. The Prophet himself did not always fast when traveling. On one journey a person was so overwhelmed by hunger that he collapsed; the Prophet disapproved when he learned that the man had been fasting. During wars the Prophet used to prevent people from fasting so that they would not lack energy for the fight. It has been reported by 'Umar that two military expeditions took place in the month of Ramadan. The first was the Battle of Badr and the second the conquest of Makka. On both occasions the Companions abstained from fasting, and, according to Ibn 'Umar, on the occasion of the conquest of Makka the Prophet proclaimed that people should not fast since it was a day of fighting. In other Traditions the Prophet is reported to have said that people should not fast when they had drawn close. to the enemy, since abstention from fasting would lead to greater strength. (See Ahmad b. Hanbal, Musnad, vol. 3, p. 329, and vol. 5, pp. 205 and 209; Darimi, `Sawm', 41; Muslim, `Siyam', 92; Nasa'i, `Siyam', 47; Bukhari, `Maghazi', 71; Muslim, `Siyam', 102; Ahmad b. Hanbal, Musnad, vol. 3, pp. 21, 35, .46; Tirmidhi, 'Sawm', 18; Nasa'i, `Siyam', 52; Bukhari, `Jihad', 29; Muslim, `Siyam', 98; Abu Da'ud, 'Sawm', 42; Muslim, `Siyam', 102, 103, 105; Ahmad b. Hanbal, Musnad, vol. 2, 99; Tirmidhi, 'Sawm', 19 - Ed.) The duration of a journey for which it becomes permissible for a person to abstain from fasting is not absolutely clear from any statement of the Prophet. (cf. relevant Traditions Abu Da'ud, 'Sawm', 46, 47; Nasa'i, `Siyam', 54, 55; Malik, Muwatta', `Siyam', 21, 27 - Ed.) In addition the practice of the Companions was not uniform. It would seem that any journey which is commonly regarded as such, and which is attended by the circumstances generally associated with traveling, should be deemed sufficient justification for not fasting. Jurists agree that one does not have to fast on the day of commencing a journey; one may eat either at the point of departure or after the actual journey has commenced. Either course is sanctioned by the practice of the Companions. Jurists, however, are not agreed as to whether or not the residents of a city under attack may abstain from fasting even though they are not actually traveling. Ibn Taymiyah favors the permissibility of abstention from fasting and supports his view with very forceful arguments. magnify Allah for what He has guided you to, and give thanks to Him. ⁵This indicates that fasting need not be confined, exclusively, to Ramadan. For those who fail to fast during that month owing to some legitimate reason God has kept the door of compensation open during other months of the year so that they need not be deprived of the opportunity to express their gratitude to Him for His great bounty in revealing the Qur'an. It should be noted here that fasting in Ramadan has not only been declared an act of worship and devotion and a means to nourish piety but has also been characterized as an act of gratefulness to God for His great bounty of true guidance in the form of the Qur'an. In fact, the best way of expressing gratitude for someone's bounty or benevolence is to prepare oneself, to the best of one's ability, to achieve the purpose for which that bounty has been bestowed. The Qur'an has been revealed so that we may know the way that leads to God's good pleasure, follow that way ourselves and direct the world along it. Fasting is an excellent means by which to prepare ourselves for shouldering this task. Hence fasting during the month of the revelation of the Qur'an is more than an act of worship and more than an excellent course of moral training; it is also an appropriate form for the expression of our thankfulness to God for the bounty of the Qur'an. Quran 2:185

Excerpted from "Towards Understanding the Qur'an". Translated and edited by Zafar Ishaq Ansari. English version of Tafhim al-Qur'an by Sayyid Abul Ala Mawdudi.

Footnotes[+]

Footnotes

↑1	Like most other injunctions of Islam those relating to fasting were revealed gradually. In the beginning the Prophet had instructed the Muslims to fast three days in every month, though this was not obligatory. When the injunction in the present verse was later revealed in 2 A.H., a degree of relaxation was introduced: it was stipulated that those who did not fast despite their capacity to endure it were obliged to feed one poor person as an expiation for each day of obligatory fasting missed (see verse 184). Another injunction was revealed later (see verse 185) and here the relaxation in respect of able-bodied persons was revoked. However, for the sick, the traveler, the pregnant, the breast-feeding women and the aged who could not endure fasting, the relaxation was retained. (See Bukhari, `Tafsir al-Qur'an', 25; Tirmidhi, 'Sawm', 21; Nasa'i, `Siyam', 51, 62, 64; Ibn Majah, `Siyam', 12; Ahmad b. Hanbal, Musnad, vol. 3, p. 104; vol. 4, pp. 347 and 418; vol. 5, p. 29 - Ed.)
↑2	This act of extra merit could either be feeding more than the one person required or both fasting and feeding the poor.
↑3	Here ends the early injunction with regard to fasting which was revealed in 2 A.H. prior to the Battle of Badr. The verses that follow were revealed about one year later and are linked with the preceding verses since they deal with the same subject.
↑4	Whether a person should or should not fast while on a journey is left to individual discretion. We find that among the Companions who accompanied the Prophet on journeys some fasted whereas others did not; none objected to the conduct of another. The Prophet himself did not always fast when traveling. On one journey a person was so overwhelmed by hunger that he collapsed; the Prophet disapproved when he learned that the man had been fasting. During wars the Prophet used to prevent people from fasting so that they would not lack energy for the fight. It has been reported by 'Umar that two military expeditions took place in the month of Ramadan. The first was the Battle of Badr and the second the conquest of Makka. On both occasions the Companions abstained from fasting, and, according to Ibn 'Umar, on the occasion of the conquest of Makka the Prophet proclaimed that people should not fast since it was a day of fighting. In other Traditions the Prophet is reported to have said that people should not fast when they had drawn close. to the enemy, since abstention from fasting would lead to greater strength. (See Ahmad b. Hanbal, Musnad, vol. 3, p. 329, and vol. 5, pp. 205 and 209; Darimi, `Sawm', 41; Muslim, `Siyam', 92; Nasa'i, `Siyam', 47; Bukhari, `Maghazi', 71; Muslim, `Siyam', 102; Ahmad b. Hanbal, Musnad, vol. 3, pp. 21, 35, .46; Tirmidhi, 'Sawm', 18; Nasa'i, `Siyam', 52; Bukhari, `Jihad', 29; Muslim, `Siyam', 98; Abu Da'ud, 'Sawm', 42; Muslim, `Siyam', 102, 103, 105; Ahmad b. Hanbal, Musnad, vol. 2, 99; Tirmidhi, 'Sawm', 19 - Ed.) The duration of a journey for which it becomes permissible for a person to abstain from fasting is not absolutely clear from any statement of the Prophet. (cf. relevant Traditions Abu Da'ud, 'Sawm', 46, 47; Nasa'i, `Siyam', 54, 55; Malik, Muwatta', `Siyam', 21, 27 - Ed.) In addition the practice of the Companions was not uniform. It would seem that any journey which is commonly regarded as such, and which is attended by the circumstances generally associated with traveling, should be deemed sufficient justification for not fasting. Jurists agree that one does not have to fast on the day of commencing a journey; one may eat either at the point of departure or after the actual journey has commenced. Either course is sanctioned by the practice of the Companions. Jurists, however, are not agreed as to whether or not the residents of a city under attack may abstain from fasting even though they are not actually traveling. Ibn Taymiyah favors the permissibility of abstention from fasting and supports his view with very forceful arguments.
↑5	This indicates that fasting need not be confined, exclusively, to Ramadan. For those who fail to fast during that month owing to some legitimate reason God has kept the door of compensation open during other months of the year so that they need not be deprived of the opportunity to express their gratitude to Him for His great bounty in revealing the Qur'an. It should be noted here that fasting in Ramadan has not only been declared an act of worship and devotion and a means to nourish piety but has also been characterized as an act of gratefulness to God for His great bounty of true guidance in the form of the Qur'an. In fact, the best way of expressing gratitude for someone's bounty or benevolence is to prepare oneself, to the best of one's ability, to achieve the purpose for which that bounty has been bestowed. The Qur'an has been revealed so that we may know the way that leads to God's good pleasure, follow that way ourselves and direct the world along it. Fasting is an excellent means by which to prepare ourselves for shouldering this task. Hence fasting during the month of the revelation of the Qur'an is more than an act of worship and more than an excellent course of moral training; it is also an appropriate form for the expression of our thankfulness to God for the bounty of the Qur'an.