Definition and Pillars of fasting
Linguistically speaking, fasting means to abstain from doing something. However, when the notion of fasting is used in Islamic Shari’a, it refers to abstaining from all the things that nullify fasting from the break of dawn (Fajr) till sunset (Maghreb), coupled with the intention of doing so as an act of worship. Fasting the month of Ramadan is obligatory (Fard) according to the Qur’an, Sunnah, and consensus of the scholars on every Muslim who has reached the age of puberty, is sane, and is able to fast without it acting as a threat to his/her health due to illness.
Allah (s.w.t) made it obligatory in the second year after the Prophet’s blessed migration from Makkah. He Most High said: “O you who believe! Observing fast is prescribed for you…” that is, it has been made obligatory upon you. It is also one of the five pillars of Islam. The Messenger of Allah (SWT) said: “Islam has been built on five pillars…” and one of them is fasting the month of Ramadan. Therefore, whosoever denies this obligation is a disbelieving apostate according to the consensus of the scholars.
As for the first pillar of fasting, this is the intention, and the place of the intention is the heart, hence articulating the intention is something not legislated. It is mandatory to have the intention at night, that is, before the break of dawn (Fajr). This is based on the saying of Prophet Muhammad (SAW): “Whoever does not intend fasting prior to Fajr, then there is no fasting for him.” (Ahmad, ibn Hibbaan, and verified as authentic by ibn Khuzaimah)
It is permissible to make an intention for the whole month at the first evening of Ramadan. However, some scholars have suggested it is obligatory to make an intention every night of Ramadan. On the other hand, if a person wanted to fast outside of Ramadan, that is, supererogatory fasting, it is permissible to make the intention at any point during the day. This is based on the saheeh (sound) hadith collected by Muslim whereby Aisha (r.a) narrated: “The Prophet (SAW) came to visit me one day and asked, ‘Do you have anything (to eat)?’ I said, ‘No.’ He said, ‘Then I am fasting.’” Even if a person intended to commence their fast moments before sunset (Maghrib), the fasting is correct. So providing none of the things that render fasting invalid are done, then the person will receive full reward, as there is nothing mentioned from the Prophet (SAW) the reward commences from the time of the intention, and Allah Most High knows best.
The second pillar of fasting is abstinence; abstaining from the things that break a person’s fast from the break of dawn till sunset, along with a continued intention between these two periods. If a person made an intention to break their fast, however does not come across anything to break their fast with from food or drink until sunset, then they must make up that day after Ramadan. This is because maintaining the intention between Fajr and Maghreb is from amongst the pillars of fasting. The third and final pillar of fasting is the time. That is, one must fast during the days of Ramadan and not the nights. For whoever fasts the nights instead of the days, then their fasting is deemed defective because Allah (s.w.t) says: “…and eat and drink until the white thread (light) of dawn appears to you distinct from the black thread (darkness of night), then complete your fast till the nightfall…” (Al-Baqarah, 2: 187)