Invalidators of Fasting

The invalidators of fasting are as follows:

1- Sexual intercourse
2- Eating
3- Drinking
4- Ejaculation of semen with desire
5- What may be regarded as (a substitute for) food and drink
6- Intentional vomiting
7- Blood coming out (of the body) by means of cupping
8- Blood coming out during menstrual and post-partum periods
As for eating, drinking and intercourse, the relevant proof is found in the noble verse that says (what means): {So now, have relations with them and seek that which Allah has decreed for you. And eat and drink until the white thread of dawn becomes distinct to you from the black thread [of night]. Then complete the fast until the sunset.} [Quran 2:187]
With regard to the ejaculation of semen with desire, the proof is the Qudsi hadith in which Allah Almighty says, "He gives up his food, drink and desire for My sake." [Ibn Majah]
Ejaculation of semen results from desire, as indicated in the hadith in which the Prophet  said, "It will be counted as a charity for you (when you have sexual relations with your wife)." They said, "O Messenger of Allah! Would one of us fulfill his desire and be rewarded?" He said, "What do you think if he had fulfilled it illegally? Would he not be punished? Likewise, if he fulfills it in a wholesome way, he shall be rewarded." [Muslim] "Fulfill his desire" is associated with semen issuing forth. That is why the more correct opinion says that the mathi (pre-seminal fluid) does not invalidate the fast even if it is emitted due to desire and sexual enjoyment, short of actual intercourse.
That which may be regarded as a substitute for food and drink includes, for example, nutritious injections. Although these are not really food or drink, they serve as a substitute and fulfill the need for them. That which can serve as a substitute for something is subject to the very ruling related to that thing. In a case like this, maintaining the body relies on taking such injections, that is, the body derives its needed nutrition from them. On the other hand, injections that do not provide nutrition or serve as an alternative for food and drink do not render the fast invalid, whether they are taken into a vein, a muscle, or any other part of the body.
The fifth point is intentional vomiting, which does invalidate the fast. This ruling is rooted in the hadith that was narrated on the authority of Abu Hurayrah, may Allah be pleased with him, in which the Prophet  said, "Whoever vomits unintentionally needs not make up for that day, and whoever vomits on purpose must make up for that day."[Abu Dawood and At-Tirmithi]
The wisdom in regarding the fast invalid on account of intentional vomiting is that the stomach becomes empty of food as a result, so the body needs to be refilled. Hence, our view is that a person observing an obligatory fast is not allowed to vomit and thereby invalidate an obligation.
The seventh invalidator is blood coming out (of the body) as a result of cupping, and the relevant proof is found in the hadith in which the Prophet  said,
"The cupper and the one to whom cupping is done have both broken their fast." [Al-Bukhari and At-Tirmithi]
The eighth invalidator is the blood coming out during menstrual and post-partum periods, and this ruling relies on the hadith that states that the Prophet  said, "Is it not true that a woman can neither pray nor fast during her menses?" [Al-Bukhari and Muslim] Scholars unanimously agree that the fast of a woman during her menstrual or post-partum period is invalid.
The above mentioned invalidators of fasting have no effect except if the following three conditions are met:
1- Knowledge
2- Remembering
3- Intention
Thus, a fasting person does not invalidate his fast through any of these invalidators except with these three mentioned conditions.
First: A fasting person should be aware of the relevant sharia ruling and the time of fasting. Otherwise, his fast is valid. This opinion is based on the Quranic verse in which Allah, the Exalted, says (what means): {...Our Lord, do not impose blame upon us if we have forgotten or erred...} [Quran 2:286], and another verse that reads (what means): {...And there is no blame upon you for that in which you have erred but [only for] what your hearts intended...} [Quran 33:5] These two are general proofs.
There are specific proofs authentically reported in the Sunnah. In an authentic hadith on the authority of `Adiyy ibn Hatim, may Allah be pleased with him, he related that he intended to fast one day and put two headbands – used to pull a camel when it kneels down – under his pillow. One headband was black, and the other was white. He kept eating and drinking until he could distinguish the black from the white, then he abstained. In the morning, he came to the Messenger of Allah  and told him what had happened. The Prophet  explained to him that what is meant by the verse is the black of the night and the white of the day. [Al-Bukhari and Muslim] He was unaware of the correct ruling given his mistaken understanding of the noble verse's meaning.
Regarding unawareness of the time of fasting, there is a hadith on the authority of Asma' bint Abu Bakr, may Allah be pleased with both of them, who said, "We broke our fast during the time of the Prophet  on an overcast day, then the sun appeared." [Al-Bukhari] Obviously, the Prophet  did not command them to make up for the fast. If they had to do so, then he would have commanded them and, had he given that order, this would have been reported to the ummah (Muslim community) as Allah Almighty says (what means): {Indeed, it is We Who sent down the Quran and, indeed, We will be its guardian.} [Quran 15:9] This command was not reported while it would have been necessary, this clearly indicates that the Prophet  did not give that command, which signifies that this is not a duty. A similar example is that of a person who wakes up after Fajr thinking that it is nighttime and eats and drinks only to later discover that the Fajr has already passed. Such a person is not obliged to make up for the fast because he was unaware of the time.
Second: A person should remember that he is fasting. If he forgetfully eats or drinks, then his fast is valid, and he does not have to make up for it. This view relies on the verse that says (what means): {...Our Lord, do not impose blame upon us if we have forgotten or erred...} [Quran 2:286] In response, Allah, the Exalted, says, "I grant this." It is also based on the hadith that was narrated by Abu Hurayrah, may Allah be pleased with him, who said that the Messenger of Allah  said, "Whoever forgetfully eats and drinks while fasting should complete his fast since only Allah gave him food and drink." [Muslim]
Third: A fasting person should be voluntarily intending to do such an act that invalidates the fast. Otherwise, his fast is valid whether he is forced or not. About disbelief due to coercion, Allah, the Exalted, says (what means): {Whoever disbelieves in Allah after his belief… except for one who is forced [to renounce his religion] while his heart is secure in faith. But those who [willingly] open their breasts to disbelief, upon them is wrath from Allah, and for them is a great punishment.} [Quran 16:106] If disbelief due to coercion is forgiven, then lesser sins or mistakes that one is forced to commit are more worthy of forgiveness. This also goes in line with the hadith that says that the Prophet  said, "Allah has forgiven my ummah its unintentional mistakes, forgetfulness, and what they are forced to do." [Ibn Majah]
Accordingly, if dust enters the nose of a fasting person and he feels its taste in his mouth and it reaches his stomach, then his fast remains valid because he did not want this to happen.
Likewise, if a fasting person is forced to break his fast and yields due to fear of some harm, then his fast is still valid because his act was involuntary. Also, the fast of a person who had a wet dream is valid since a sleeping person has no intention. As such, the fast of a wife whose husband forces her into sexual intercourse is valid as she did so involuntarily.
It is worthy to draw attention to a certain point: What if a man breaks his fast during the daytime in Ramadan with sexual intercourse while he is obliged to fast? This would entail the following five things:
First: Sin.
Second: He should still fast the rest of the day.
Third: His fast becomes invalid.
Fourth: He is required to make up for that fast.
Fifth: He is required to offer an expiation.
It makes no difference whether or not such a person knows the consequences of such intercourse. In other words, if a man copulates with his wife during the daytime in Ramadan while he is obligated to fast but is unaware that an expiation will be required of him as a result, then he will still be subject to all the relevant requirements mentioned above. This is because he engaged in the fast-invalidating act intentionally, so the stipulated requirements apply. This is even more powerfully indicated in a hadith on the authority of Abu Hurayrah, may Allah be pleased with him, who narrated that a man came to the Prophet  and said, "O Messenger of Allah! I am ruined." The Prophet  said: "What is the matter?" He said, "I had sexual relations with my wife while observing the Ramadan fast." [Al-Bukhari and Muslim] As a consequence, the Prophet  commanded him to expiate even though the man was not previously aware that he would be required to do so. Moreover, in the words, "while he is obligated to fast," we are adopting a cautious approach lest a fasting person has sexual relations while he is traveling, in which case he is not required to offer an expiation. A traveler who is fasting is not obliged to complete it. If he wills, he may complete his fast, or he may break it and make up for it later.
Allah knows best, and to Him everything shall return.
And may the peace and blessings of Allah be upon our Prophet Muhammad  and all his household and Companions.