The actions that void the fast may be divided into two types:
1. those which void the fast and require that the day be made up later, and
2. those which void the fast and, in addition to being made up, also require an act of expiation.
Intentional eating or drinking:
If one eats due to forgetfulness, a mistake, or coercion, then he does not have to make up the day later or perform any expiation. Abu Hurairah reported that the Prophet said: "Whoever forgets he is fasting, and eats or drinks is to complete his fast, as it was Allah who fed him and gave him something to drink." This is related by the group.
Commenting on it, at-Tirmidhi says: "Most of the scholars act according to this hadith. It is the opinion of Sufyan ath-Thauri, ash-Shaf'i, Ahrnad, and Ishaq."
Abu Hanifah reported that the Prophet said: "Whoever breaks his fast during Ramadan due to forgetfulness is not to make up the day later or to perform any expiation." This is related by ad-Daraqutni, al-Baihaqi, and al-Hakim, who says that it is sahih according to Muslim's criterion. Ibn Hajr says that its chain is sahih.
Ibn 'Abbas reported that the Prophet said: "Allah will not hold anyone of this nation responsible for what is done in error, forgetfulness or under coercion." This is recounted by Ibn Majah, at-Tabarani, and al-Hakim.
Fasting, intentional vomiting:
If one is overcome and vomits unintentionally, he does not have to make up the day later on or perform the acts of expiation. Abu Hurairah reported that the Prophet, upon whom be peace, said: "Whoever is overcome and vomits is not to make up the day." Whoever vomits intentionally must make up the day." This is related by Ahmad, Abu Dawud, at-Tirmidhi, Ibn Majah, Ibn Hibban, ad-Daraqutni, and al-Hakim. The latter called it sahih.
Of the report's credibility, al-Khattabi says: "I do not know of any difference of opinion among the scholars on this point. If one vomits unintentionally he is not in need of making up the day, while one who vomits intentionally must make up the day later."
Fasting, the menses and post-childbirth bleeding:
Even if such bleeding begins just before the sunset, the fast of that day is rendered void and the day must be made up. There is a consensus of scholars on this point.
Fasting, ejaculation of sperm:
Ejaculation voids the fast even if it was just due to kissing, hugging, or masturbation, and the day must be made up. If the ejaculation was due to looking at or thinking about something, then it is like having a wet dream during the day and it, therefore, does not void the fast nor is there any requirement on the person. Similarly, ejaculation of seminal fluid does not harm the fast in any way.
Eating something that is not nourishing, such as salt:
Someone who uses a lot of salt for a reason other than eating, in which it goes down to the stomach, breaks the fast according to most scholars.
If one has the intention, while he is fasting, to break the fast, he in effect voids the fast even if he does not actually eat anything: This is because the intention is one of the pillars of the fast and, if one changes his intention, he has nullified his fast.
If one eats, drinks, or has intercourse, thinking that the sun has set or that fajr has not occurred: In such cases, according to most scholars and the four imams, that person is to make up that day. However, there is a difference of opinion on this point. Ishaq, Dawud, Ibn Hazm, 'Ata, 'Urwah, al-Hassan al-Basri, and Mujahid maintain that such a fast is sound and that the person need not make up the day later. They base their opinion on the fact that Allah says in the Qur'an: "And there is no sin for you in the mistakes you make unintentionally, but what your hearts purpose [that will be a sin for you]."
The Messenger of Allah, upon whom be peace, said: "Allah will not hold anyone of this nation responsible for what is done by mistake . . ."
'Abdurrazaq related that Mamar reported from al-Amash that Zaid ibn Wahb said: "The people broke their fast during the time of 'Umar ibn al-Khattab. I saw a big pot being brought from Hafsah's house and the people drank. Then the sun appeared from behind the clouds and this distressed the people. They said: 'We have to make up this day.' 'Umar asked: 'Why? By Allah, we have not involved ourselves in any sin.' "
Al-Bukhari records that Asma' bint Abu Bakr said: "We broke the fast of Ramadan when it was cloudy during the time of the Prophet, and then the sun appeared again."
Commenting on the subject, Ibn Taimiyyah says: "This points to two things:
1. that it is not preferred for one to delay breaking the fast until one is absolutely certain that the sun has set . . . and
2. that it is not necessary to make up such a day. If the Prophet would have ordered them to make up that day, it would have become public knowledge. The fact that it has been related that they broke their fast [and that it has not been related that they were ordered to make up that day] points to the fact that they were not ordered to make up that day."
The only action, according to most scholars, which requires that both the day be made up and the act of expiation be performed is having sexual intercourse during a day of Ramadan.
Abu Hurairah reported that a man came to the Messenger of Allah and said: "I am destroyed, O Messenger of Allah!" The Prophet asked: "What has destroyed you?" He said, "I had intercourse with my wife during a day of Ramadan." The Prophet asked: "Are you able to free a slave?" He said, "No". The Prophet asked: "Is it possible for you to fast for two consecutive months?" He said, "No." The Prophet asked: "Is it possible for you to feed sixty poor people?" He said, "No." The Prophet said: "Then sit." A basket of dates was brought to the Prophet and he said to the man: Give this in charity. The man said: "To someone poorer than us? There is no one in this city who is poorer than us!" The Prophet laughed until his molar teeth could be seen and said: "Go and feed your family with it." This is related by the group.
Most scholars say that both men and women have to perform the acts of expiation if they intentionally have intercourse during a day of Ramadan on which they had intended to fast. If they had intercourse out of forgetfulness or not due to choice--that is, due to coercion, or they did not have the intention to fast, then the expiation is not obligatory on either one of them. If the woman was forced to have intercourse by the man, the expiation will be obligatory only upon the man.
According to ash-Shaf'i, the expiation is not obligatory upon the woman in any case--that is, regardless if it was due to choice or coercion, and she need only make up the day of fasting that she voided. An-Nawawi says: "The most authentic opinion, in general, is that the expiation is obligatory upon the man only and that there is nothing upon the woman. There is nothing obligatory on her in relation to this matter, as it is a matter of [paying] money [due to something related to] sexual intercourse and this refers to the duty of the man and not the woman. [In this way,] it is similar to the case of dowry."
Abu Dawud says: "Ahmad was asked about someone who had sex during Ramadan: 'Is there any expiation upon the woman?' He said: 'I have not heard of any.' " In al-Mughni it is stated: "This refers to the fact that the Prophet ordered the man who had had sexual intercourse to free a slave. He did not order the woman to do anything, although he obviously knew that she was a partner in the act."
According to most scholars, acts of expiation must be performed in the order that was mentioned in the hadith. The first command is to free a slave. If this is not possible, the person is to fast for two consecutive months. If that is not possible, the person is to feed sixty poor people with meals that are similar to an average meal in his household. The person cannot jump from one act to another unless he is not able to perform the prior order commanded. According to the Malikiyyah and a narration from Ahmad, the person is free to choose any of the above three acts and that will be sufficient for him.
This latter opinion is based on the report from Malik and Ibn Juraij on the authority of Humaid ibn 'Abdurrahman who reported that Abu Hurairah narrated that a man broke his fast during Ramadan and the Prophet ordered him, as an expiation, to free a slave or fast two months consecutively or to feed sixty poor people. This is related by Muslim.
In the preceding hadith, the word "or" implies choice, but according to some, the reason for the expiation to be performed was different and therefore the person could choose, as in the case of the expiation for breaking an oath. Ash-Shaukani says: "In the different narrations, there is evidence that the expiation is to be performed in order or according to one's choice. Those who relate it to be in order are more in number. Al-Muhallab and al-Qurtubi combined the narrations and said that the event [of someone breaking the fast] occurred more than once."
Al-Hafidh differs: "This is not correct. It was just one event and the parts are all united. So the crux of the matter is that there was not more than one event. Some combine the reports and say that following the order is preferred, but that one may choose. Others say the opposite."
Whoever has sexual intercourse (with his wife) on a day of Ramadan and, before he performs the act of expiation, has intercourse on another day of Ramadan, need only perform one act of expiation according to a narration from Ahmad and the Hanafiyyah. This is because there is a punishment for acts that are repeated, and if the expiation or punishment is not carried out, all the acts are taken together as one. According to Malik, ash-Shaf'i, and Ahmad, the person must perform the expiation twice, as each day of Ramadan is a separate act of worship. If the expiation is obligatory because the person voided the fast, the separate acts are not combined together.
All scholars agree that if the person intentionally had intercourse during a day of Ramadan and has performed the expiation and then has intercourse on another day of Ramadan, then another expiation becomes obligatory upon him. Similarly, they are in agreement that if one has intercourse twice during a day, before performing the expiation for the first act, then he need only perform one act of expiation. If he has performed the expiation for the first one, then he need not perform an act of expiation for the second, according to most scholars. Ahmad says that in such a case, he must perform a total of two acts of expiation.