The person who fasts should abstain from down the flowing:
1) Food, drink and sexual intercourse from dawn until sunset, In accordance with the verse of the Quran : "Now therefore go unto them and seek what Allah has ordained for you, and eat and drink until the white thread of dawn be comes distinct from the black thread, then observe the fast till nightfall".
The black thread means the darkness of night and the white thread means the light of day at dawn.
Every Muslim may, during the night, satisfy his needs with regard to food, drink and women when dawn comes he must abstain till sunset.
Smoking, drug taking and the injection of nourishing solutions into the body (e.g. calcium or vitamins) are strictly forbidden.
Sexual intercourse must be followed by complete ablution, i.e. a bath covering all parts of the body.
The Prophet forbade Muslims who are fasting to indulge in any of the following :
(a) Obscene speech. The Prophet said: "While fasting, you shall not indulge in obscene speech or boisterous talk. If someone insults you or quarrels with you, tell him : `I am one who fasts. "
b) Falsehood in speech or action. The Prophet said : "He who does not abstain from false- hood in words or deeds, God has no need for him to abstain from his food and drink."
c) Slander. One day the Prophet passed by women who, while fasting, were gossiping.
He said : "These two women abstained from what God had ordered them to do an
indulged in what God had forbidden them to do".
(d) Lying, lustful looks, false oath, slander and calumny. The Prophet said : "Five things spoil a man's fast - lying, slander, calumny, the false oath and the lustful look."
Some ulama believe that those forbidden things spoil one's fast. They base their verdict on the Prophet's warning that "five things spoil a man's fast... etc." and other ravings mentioned earlier. They also base their verdict on a definite quotation. The Prophet said :"there may be a man whose gain from his fast is confind to hunger and thirst" These `ulama include Ibn Hazm and the late rector of AI-Azhar, Sheikh Mahmoud Shaltout,
A second group of `ulama blieve that these forbidden things do not spoil the fast, but abstention from them makes one's fast more complete.
The Prophet's Companions had different opinions as to the fast of doubtful days. Some of them permitted it, whilst is others forbade it. The opinion of the opposite has more weight because of a verdict pronounced by Abu Ammar to the effect that "whoever fasts a doubtful day would, in fact be disobeying the Prophet."
However, a man is permitted to fast, a doubtful day. should such a day fall within the number of days which a man has been actually fasting. The Prophet's instruction in this connection is : "No man shall fast one or two days before Ramadan, unless he was already observing a fast".
It is the custom of the Muslims to look: for the crescent moon on the evening of 29th of Sha'ban. If it does not appear, the following day is considered a doubtful day being neither the end of Sha'ban nor the beginning of Ramadan. The Muslims are not allowed to fast on such a day.
1) Ramadan fast is spoiled if a person deliberately eats, drinks, or indulges in sexual intercourse.
a) Deliberate eating or drinking, spoils the fast and necessitates asking for forgiveness.
b) Deliberate sexual intercourse spoils the fast and necessitates qada (restitution) of an other days' fast in place of it as well as Kaffara (atonement).
Kaffara is to set free a slave, or a fast of two consecutive months,or the feeding of sixty poor people. This is based on the following story:
"A man told the Prophet : "I have commited a deadly sin.
The Prophet asked : "what was it ?"
The man said : "I slept with my wife during Ramadan
"Have you any slave to set free?" the Prophet asked.
"No," answered the man.
"Can you fast for two consecutive months ?" the Prophet asked.
"No," said the man.
Can you afford to feed sixty poor people ?
"No," again replied the man.
Whereupon the Prophet went into his house, brought some dates and told the man : "Take these and give them to some poor people."
The man asked :"Can I find any poorer than my own family ?"
Laughing the Prophet said: "Then, take the to your family."
As for restitution, Abu Da'ud al- Athram and Ibn Maja reported that the Prophet had ordered the man who, slept with his wife during Ramadan fast to fast another day instead, in addition to the Kaffara.
2) Fasting is also spoiled if a person deliberately vomits.
In this case he has to fast a day in restitution. Abu Hurayra reported that the Prophet had said "He who forces himself to vomit shall fast another day instead".
1) Involuntary vomiting. Abu Hurayra reported that the prophet had said "He who is overcome by vomiting shall not make restitution".
2) The cupping of blood from the head. Thabit Al Bannani asked Anas Iba Malik : "Did the Prophet forbid head bleeding for the person who fasts ?" Anas said : "Not unless a person is weak".
3) Wet Dreams. The Prophet is reported to have said that "a man's fast is not spoiled for in voluntary vomiting or wet dreams."
4) Unintentional eating or drinking. The Prophet said : "Allah forgives my people for acts committed by mistake, or out of absent mindedness, and acts performed under compulsion." He also said that, "a man who fasts and who absent mindedly eats or drinks shall continue his fast."
5) Rinsing the mouth and bathing in an attempt to reduce the effect of the summer heat. One of the Prophet's companions reported that he used "to see the Prophet pour water on his head while he was fasting".
6) If a man gets up in the morning in a state of ritual uncleanliness it does not affect his fast.
7) A man who eats, drinks or sleeps with his wife thinking that it is still before dawn. The same applies if he thinks that it is after sunset. There are two opinions in this respect:
(a) The fast is valid, for Allah said:
"You are not to blame for what you do by mistake, but you are for premeditated acts".
Zayd Ibn Wahb is reported to have said: "People broke the fast during the time of Omar Ibn al-Khattab I have seen water vessels, brought from the house of Hafsa, from which the people drank. Immediately, the sun appeared from behind a cloud. The people wanted to fast another day in restitution, but Omar intervened. "Why ?" he asked. "By Allah, we did not mean any wrong".
(b) The other school of thought makes restitution imperative.
Kohl does not spoil the fast. The Prophet is reported to have used it while fasting in Ramadan.
The rule about Kohl applies to eye drops ,eye drops, or nose drops even if they reach the throat. This rule also covers snuff, road dust, intravenous, muscular, or subcutaneous injections. Some scholars have included enema under this heading because it comes out again, drawing forth that which it is intended that it draws out. The rule even applies to the smelling of strange scents, to chewing gum, or tasting food, provided nothing of it reaches the stomach. Abu Muhammad Ibn Hazm summed it up as follows:
"Allah forbade us, during the fast, from eating, drinking, sexual intercourse, deliberate vomiting and sins. We know of no food or drink which could be consumed through the anus, urethra, ear, eye, nose from a wound in the abdomen or head. Apart from food and drink we are not prohibited from letting anything reach the stomach".