These Quranic verses and Ahadeeth are the core and foundation of the rulings/concessions that are to be mentioned below. This is because those with legal excuses are not like those without excuses.
Furthermore, those who have legal excuses cannot establish prayer as completely as those without excuses. Therefore, the Lawgiver has lightened the hardship for the excused Muslims and ordered them to perform prayer as much as they can, sometimes however they can based on their various situations and circumstances.
These rulings show the ease and relief intended for the Muslims in the Shari’ah (Islamic Law), as it always eliminates hardship and this is from the favor and blessings of Allah upon His servants. The excuses that validate one to miss congregational prayer are:
1. Winter or Harsh Weather Conditions – Cold and Rain Night or Day
Nafi narrated that on a cold and windy night, Ibn Umar made the call to prayer and announced during it, “Pray in your homes.” Then he said, “The Messenger of Allah would tell the caller to prayer on cold and rainy nights to say, “Pray in your homes (dwellings).” [Saheeh al-Bukhari, Saheeh Muslim, Abu Dawood and an-Nasa’i]
It was narrated that ‘Abd-Allah ibn ‘Abbaas said to his muezzin on a rainy day: “When you say: I bear witness that there is no god but Allah and I bear witness that Muhammad is the Messenger of Allah, do not say, Come to prayer, rather say: Pray in your houses. It was as if the people found that strange, so he said: Are you surprised by that? One who is better than me did
that. Jumu’ah is obligatory, but I did not want to force you to walk in the mud and on slippery ground.” [Saheeh al-Bukhari]
Comments: These ahadeeth indicates in the event of a heavy rain which makes it difficult for people to go to the Masjid, congregational prayer may be skipped. It also indicates the Messenger of Allah did not want to place any difficulty on the people. He granted this concession of offering prayer at home because of rain and cold. Also included in this is when there are strong winds, hurricane, storm, severe cold, severe rain and mud etc.
Ibn Bataal said, “The scholars are unanimously agreed that it is permissible to remain away from the congregational prayer due to heavy rain, darkness, wind and other such things.” [Ibid]
2. When One’s Meal is Presented/Served (while he is in need of it or hungry)
Ibn Umar narrated that the Messenger of Allah said, “If your dinner is presented to you and the prayer is commenced, begin with your dinner and do not be hasty until you finish it.” Thus, if the dinner was presented to Ibn Umar and the prayer would start, he would not go to the prayer until he had finished, even though he could hear the reciting of the Imam. [Saheeh al-Bukhari, Saheeh Muslim (without the statement about Ibn Umar), and Abu Dawood]
Comments: This hadeeth and the one below indicate that if one is served food or has already started eating food while he is in need of it (i.e. he is hungry) he should not hurry and eat until his need has been fulfilled, even if the prayer has commenced. Not doing so would be opposing the Prophets guidance and command, furthermore, it will lead to lack of concentration in prayer.
3. When needing to relieve oneself – The Call of Nature
Aishah (radhiallahu 'anha) narrated that she heard the Messenger of Allah (sallallahu 'alayhi wa sallam) say, “There is no prayer when the food has been served or when one is repressing the urge to relieve himself (i.e. go to the toilet).”
[Saheeh. Saheeh al- Jami as-Sagheer. Recorded by Muslim and Abu Dawood]
Comments: This hadeeth indicates that when one has the urge to go to the toilet, he should not restrain oneself from excreting or urinating even if the prayer has started, rather, he should relieve himself first then go to attend the prayer. This is because not relieving oneself would distract one from the prayer and prevent him from having khushoo in prayer. Furthermore, he would be opposing the Prophets guidance. If he catches the congregational prayer then Alhamdulillah, if not then he is not sinful since he had a valid/legal excuse.
Shaykh Ibn Uthaymeen was asked: If a person feared that if he answered the call of nature, he would miss the congregational prayer, should he pray while he is holding it in, in order to catch the congregational prayer, or should he answer the call of nature, even if he misses the congregational prayer?
Answer: He should answer the call of nature and then make ablution, even if he missed the congregational prayer, because this is an excuse and the Prophet said: "There is no prayer when food is served nor when he is suppressing the two filths."
[Muslim – Shaykh Ibn Uthaimeen, Fatawa Arkanu-ul-Islam, Volume 2, pg. 496]
4. Being Overcome with Sleep
5. Forgetting to Pray
Anas bin Malik (radhiallahu 'anhu) reported that the Messenger of Allah (sallallahu 'alayhi wa sallam) said, “Whoever forgets a prayer or sleeps through it, then the expiation is to perform it when he remembers it.” [Saheeh Muslim, an-Nasa’i]
Abu Qataadah (radhiallahu 'anhu) reported that the Messenger of Allah (sallallahu 'alayhi wa sallam) said, “There is no negligence in sleep. Negligence exists only in the state of wakefulness. Therefore, if one of you forgets to pray, let him pray as soon as he remembers and let him pray the prayers of the next day at their correct times…”
[Saheeh Muslim, Abu Dawood, Trimidhee, an-Nasa’i]
Comments: Also the hadeeth that states “The pen has been lifted from three…the one who is sleeping until he wakes up (awakens)” These ahadeeth indicate that sleep and forgetfulness are valid reason. So in this situation the act of missing the prayer is not a sin and one is not held accountable as long as it was not done intentionally/deliberately and it is not a habit (i.e. it is not ones habit to sleep during prayer times and missing prayer due to it). One should take the necessary means to avoid missing prayer by sleeping early, not sleeping at the wrong time (before prayer), putting an alarm, asking someone to wake you up etc.
The one who forgot to pray or slept through it must perform prayer immediately when one remembers it or when reminded and for the one who slept when he wakes up (without further delay).
6. Illness/Sickness
The Prophet (sallallahu 'alayhi wa sallam) said, when he became severely ill and left off praying with the people for many days, “Command Abubakar to lead the people in prayer.” [Saheeh al-Bukhari] The 
statement of Ibn Masood (radhiallau 'anhu) "I have seen the time when no one among us (i.e. the companions) stayed away from prayer (i.e. would not attend the prayers in
congregation) except a hypocrite, whose hypocrisy was well known, or the sick" [Saheeh, Irwa Al-Ghaleel 2/233 no. 549]
Comments: The meaning of illness here is that illness which makes it not possible or difficult for one to attend the congregational prayer such as: the one who has chronic or bed ridden diseases, the one who has hands and foot cut off, the paralyzed, the one in a comma, and the old man who is not able to attend and the likes. This excuse also applies to one who is attending to another (that is dependent on him), if he leaves him to pray in congregation he would die or be seriously injured. Therefore, the congregational prayer is not obligatory upon people with such illness. However, Illness here does not include slight illnesses such as slight headache, flu, cough etc.
7. Fear
The evidence for Fear and Illness is based on the hadeeth of Ibn Abbas & Tariq ibn Shihab (radhiallahu 'anhum). Ibn Abbas reported that the Prophet (sallallahu 'alayhi wa sallam) said, “Whoever hears the call to prayer and does not respond, then there is no prayer for him unless he has an excuse.” They asked, “What constitutes an excuse O Messenger of Allah?” He replied, “Fear or illness.” [as-Sunan al-Kubraa by al-Bayhaqee]
Tariq ibn Shihab narrated that the Prophet (sallallahu 'alayhi wa sallam) said, “The Friday prayer is a duty and obligation upon every Muslim in the community except four: a slave, a woman, a child (non-adult) or a sick person.”
[Shaykh al-Albani, Saheeh Sunan Abu Dawood and Saheeh al-Jami as-Sagheer]
Comments: Fear in the hadeeth above means – Fears for himself, his wealth or property, his honor/family. Examples would be: Fear that if he prays in the masjid he would be killed (on his way or in the masjid) like in places or countries that are not safe, lack security, experiencing chaos and war; or that he would be harmed; or that he would be caught and jailed unjustly or
unlawfully or oppressively. This also applies to one who is attending to a sick person (that is dependent on him), if he leaves him to pray in congregation he would die or be seriously hurt.
Ibraheem an-Nakhae’ee said, “They did not use to allow anyone to miss the congregational prayer unless he were sick or in fear.” [al-Musanaaf by ibn Abee Shaybah]
Moosaa Richardson: This is acceptable, however it should be known that the very point of reference the compiler has used for a proof is perhaps unauthentic. Shaykh Al-Albaanee authenticated the hadeeth in Sunan Abee Daawood (551), and exempted the explanation of what an excuse is.
8. Traveler
Ibn 'Umar narrated that the Prophet (sallallahu 'alayhi wa sallam) said, “There is no Friday prayer upon the traveler.”
[al-Daraqutni]
Moosaa Richardson: The scholars consider a reference to Ad-Daaraqutnee alone to be an indication of the weakness of a hadeeth.
Comments: The above narrations (by Tariq and Ibn Umar) indicate that the Friday prayer is an individual obligation upon every Muslim except for five (who are exempted): a slave, a woman, a child, an ill person and a traveler. Similarly, these people are not required/obliged to pray their five daily prayers in congregation either, and are permitted to pray them at home.
Secondly, additional proof that the above are considered valid reason (Illness & Traveler) is the fact that the scholars have *differed on the issue of congregational being prayer being obligatory, however, the scholars have all agreed (consensus) to the obligation of Jumu’ah (Friday) prayer. Therefore, if the above have been excused from Friday prayer, it is more so the case with the congregational prayer.
*This does not mean one has the freedom to choose the opinion that suits his desires.
Furthermore, the correct and strongest opinion based on authentic evidences and practice of the righteous salaf is that congregational prayer is an individual obligation (fard ‘ayn) upon every Muslim.
Moosaa Richardson: This point is acceptable. However, there are a lot better choices of evidences to use to establish this point.
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