Fasting Ramadan is personally obligatory for every Muslim who has reached puberty, is sane, and is able to fast. It is not obligatory for a non-Muslim, a child, an insane person, or someone unable to fast (such as someone of advanced years or someone who is continuously sick).

Fasting has only two integrals: (1) the intention and (2) abstention from the nullifiers of the fast.

The intention is to intend to fast. Its location is in the heart, but it is sunna to say it with the tongue. One optimally says, "I intend to fast tomorrow as a current performance of the obligation of this year's Ramadan for Allah Most High." For the obligatory fast, it is obligatory to make the intention during any part of the night (from sunset until just before dawn). A practical way to avoid forgetting the intention is to intend to fast the following day immediately after breaking one's fast at sunset. Whoever forgets to make the intention, or sleeps before sunset and does not wake up until after dawn must abstain from the nullifiers during that day and then make it up after Ramadan. For the supererogatory fast, it is permissible to delay the intention until just before the noon prayer [zuhr], provided that that one has not already done something that nullifies the fast. It is obligatory to repeat the intention to fast for every day of Ramadan. It is good practice to intend during its first night to fast the whole month, so that one's fast will still be valid in the school of Imam Malik (Allah have mercy on him) if one forgets the intention on a particular day.

2.2.1 Nullifier #1: A substance reaching the body cavity through an open orifice (substance: this excludes mere traces such as mere taste or smell without any actual substance; body cavity: like the stomach, throat, norm, head, and inside of the ear; open orifice: like the mouth, nose, ear, and anus) If one deliberately and willingly allows food, drink, or anything else (even if inedible) into the body cavity through one of the aforementioned orifices, and one knew that this was unlawful, one's fast is nullified. If one does this forgetfully, under coercion, or in ignorance of its unlawfulness, one's fast is not thereby nullified. Related Issues: Someone whose gums bleed must obligatorily wash his mouth thoroughly with water. Spitting is not sufficient.

1. It is permissible to swallow one's saliva and one's fast is not thereby nullified unless it is admixed with something else such as blood from the gums or food that remains in one's mouth, in which case one invalidates one's fast by swallowing it deliberately.

2. The ruling of mucus and phlegm is that if one is able to spit it and take it out, it is obligatory to do so.

3. If one rinses the mouth during ablution [wudu] without exaggeration and some water reaches the body cavity, one's fast is not nullified. But if one rinses the mouth for other than the ablution (such as to cool off or for cleanliness) and water reaches the body cavity, one's fast is nullified even if one did not exaggerate. Similarly, if one rinses the mouth during ablution and exaggerates in doing so (by gargling, for example), one's fast will be nullified if any water reaches the body cavity.

4. If one performs an obligatory purificatory bath [ghusl] (such as for major ritual impurity or menstruation) or a recommended one (such as for the Friday prayer) and water reaches the inside of the ears, one's fast is not nullified (if it is without exaggeration and without diving in river).

5. There is no harm in swallowing saliva after rinsing the mouth even if moisture from the water remains in one's mouth and one's fast is not nullified because it is difficult to avoid.

6. It is permissible (although disliked) to taste food with the edge of one's tongue, provided nothing reaches the body cavity.

7. Smoking nullifies the fast.

8. If street dust, flour chaff, or car smoke reaches the body cavity, or if one is standing beside someone else who is smoking, one's fast is not nullified.

9. Nose-drops nullify the fast.

10 . An anal suppository will nullify the fast so if one is able to delay it until after sunset, it is obligatory to do so. If one needs it during the day, however, and is unable to delay it, one may take it and it is obligatory to perform a make up fast instead of that day.

11. Entering a stick in order to clean the inside of the ear nullifies the fast.

12. The inhaler used by asthma patients nullifies the fast because particles like drops of water come out of it and mix with his saliva, after which the patient swallows it, causing him to break his fast.

2.2.2 Nullifier #2: Vomiting deliberately. Deliberately inducing vomit from one's stomach nullifies the fast. If, however, vomit overcomes one and exits without one's choosing, the fast is not nullified.

2.2.3 Nullifier #3: Sexual intercourse even if there is no ejaculation. Both the man and the woman thereby nullify their fast, provided they remembered that they were fasting. Related Issue: If one is having intercourse with one's wife and dawn enters and one immediately disengages, one's fast is valid. If one continues having intercourse, one's fast is nullified even if one is unaware of the entrance of dawn.

2.2.4 Nullifier #4: Ejaculation caused by masturbation using the hand nullifies the fast even if done from behind a barrier (note that masturbation is unlawful even when one is not fasting).

2.2.5 Nullifier #5: Menstruation The fast of a woman who begins the morning in a state of purity and then begins menstruation is nullified. It then becomes unlawful for her to abstain from the nullifiers with the intention of fasting. It is not, however, unlawful if she abstains from them without intending to fast. A woman who begins the morning in menstruation and then becomes pure during the day is not obliged to abstain from the nullifiers for the rest of the day, although it is sunna for her to do so.

2.2.6 Nullifier #6: Insanity. If the fasting person becomes insane during the day of Ramadan (even if only for a slight moment), his fast is nullified.

2.2.8 Notes regarding the nullifiers:

1. Whoever does one of these nullifiers forgetfully, or in ignorance of its unlawfulness, his fast is not nullified, although ignorance of the rulings of the sacred law is not an excuse for someone who has access to scholars and muftis.

2. It is obligatory to abstain from these nullifiers starting from true dawn. If there is food or drink in his mouth, it is obligatory for him to spit it out. Some of the unlearned continue to eat and drink until the end of the adhan and this is a grave mistake that nullifies the fast.

3. Whoever obstinately [muta'addiyan] nullifies his fast through eating, drinking, or another nullifier without excuse is sinful and it is obligatory for him to abstain for the remainder of the day. He must make up a day in place of the one he nullified, provided it did not happen through intercourse. If he nullified it through intercourse, it is obligatory for him to make up the day he nullified and to also perform an expiation, as explained later on.

4. Whoever eats, drinks, or has intercourse thinking it merely probable that the sun has set without attaining confidence that it actually has set, must obligatorily make up that day. Whoever eats, drinks, or has intercourse thinking it probable that it is still nighttime and it subsequently learns that dawn had entered, his fast is nullified and he must abstain from the nullifiers of the fast for the rest of the day and make up the missed fast.