'Ashura is the 10th day of Muharram

Praise be to Allah, the Lord of the Worlds; and blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.
Ashura in History

Ibn 'Abbas, may Allah be pleased with him, reported that the Prophet, peace be upon him, came to Madinah and saw the Jews fasting on the day of 'Ashura. He asked:

"What is this?"

They said: "This is a righteous day, it is the day when Allah saved the Children of Israel from their enemies, so Musa fasted on this day." He said:

"We have more right to Musa than you," so he fasted on that day and commanded [the Muslims] to fast on that day. [Reported by al-Bukhari, 1865]

"This is a righteous day" – in a report narrated by Muslim, [the Jews said:] "This is a great day, on which Allah saved Musa and his people, and drowned Pharaoh and his people."

"Musa fasted on this day" – a report narrated by Muslim adds: " ... in thanksgiving to Allah, so we fast on this day."

According to a report narrated by al-Bukhari: " ... so we fast on this day to venerate it."

A version narrated by Imam Ahmad adds: "This is the day on which the Ark settled on Mount Judi, so Nuh fasted this day in thanksgiving."

" ... and commanded [the Muslims] to fast on that day" – according to another report also narrated by al-Bukhari, he said to his Companions:

"You have more right to Musa than they do, so fast on that day."

The practice of fasting on 'Ashura was known even in the days of Jahiliyyah, before the Prophet's mission. It was reported that 'Aishah, may Allah be pleased with her, said:

"The people of Jahiliyyah used to fast on that day ... "

Al-Qurtubi said:

"Perhaps the Quraysh used to fast on that day on the basis of some past law, such as that of Ibrahim, upon whom be peace."

It was also reported that the Prophet, peace be upon him, used to fast on 'Ashura in Makkah, before he migrated to Madinah. When he migrated to Madinah, he found the Jews celebrating this day, so he asked them why, and they replied as described in the hadith quoted above. He commanded the Muslims to be different from the Jews, who took it as a festival, as was reported in the hadith of Abu Musa, may Allah be pleased with him, who said:

"The Jews used to take the day of 'Ashura as a festival [according to a report narrated by Muslim: the day of 'Ashura was venerated by the Jews, who took it as a festival. According to another report also narrated by Muslim: the people of Khaybar (the Jews) used to take it as a festival and their women would wear their jewellery and symbols on that day]. The Prophet, peace be upon him, said:

'So you [Muslims] should fast on that day.' " [Reported by al-Bukhari]

Apparently the motive for commanding the Muslims to fast on this day was the desire to be different from the Jews, so that the Muslims would fast when the Jews did not, because people do not fast on a day of celebration. [Summarized from the words of al-Hafidh Ibn Hajar, may Allah have mercy on him, in Fath al-Bari)

Fasting on 'Ashura was a gradual step in the process of introducing fasting as a prescribed obligation in Islam. Fasting appeared in three forms. When the Messenger of Allah, peace be upon him, came to Madinah, he told the Muslims to fast on three days of every month and on the day of 'Ashura, then Allah made fasting obligatory when He said (interpretation of the meaning):

" ... observing the fasting is prescribed for you ... " [Al-Qur'an 2:183] [Ahkam al-Qur'an by al-Jassas, Part 1]

The obligation was transferred from the fast of 'Ashura to the fast of Ramadhan, and this one of the proofs in the field of Usul ul-Fiqh that it is possible to abrogate a lighter duty in favour of a heavier duty.

Before the obligation of fasting 'Ashura was abrogated, fasting on this day was obligatory, as can be seen from the clear command to observe this fast. Then it was further confirmed later on, then reaffirmed by making it a general command addressed to everybody, and once again by instructing mothers not to breastfeed their infants during this fast. It was reported from Ibn Mas'ud that when fasting Ramadhan was made obligatory, the obligation to fast 'Ashura was lifted, i.e., it was no longer obligatory to fast on this day, but it is still desirable (mustahabb).
On this day Prophet Muhammad (Blessings and peace of Allah be upon him) fasted in Makkah with Quraish. When He migrated to àl-Madinah, he found the Jews fasting on this day. He continued fasting on that day and ordered the Muslims to fast too. Afterward Allah legislated the fasting during the Month of Ramadan. Then, the fast of 'Ashura became a supererogatory fast. But it is likable for a Muslim to fast on this day. If one fasts on this day, it is better to fast the 9th of Muharram also to oppose the Jews.

The pieces of evidence for this point are as follow:
1 - Imam al-Bukhari and Muslim narrated from 'Aisha ( may Allaah be pleased with her) that she said: "The tribe of Quraish used to fast on the day of 'Ashura in the pre-Islamic period, and Allah's Apostle too, used to fast on that day. When he came to al-Madinah, he fasted on that day and ordered others to fast too. Later, when fasting of the Month of Ramadah was prescribed, he (the Prophet) said: "Whoever wishes may fast -'Ashura- and whoever wishes may leave it" .

2 - Ibn Abbas related : When the Prophet Muhammad (Blessings and peace of Allah be upon him) came to Madinah, he found (the Jews) fasting on the day of 'Ashura' (i.e. 10th of Muharram). They used to say: 'This is a great day on which Allah saved Moses and drowned the folk of Pharoah. Moses observed the fast on that day as a sign of gratitude to Allah. The Prophet Muhammad (Blessings and peace of Allah be upon him) said: "I am closer to Moses than them". So, he observed the fast (on this day) and ordered the Muslim to fast on it". [al-Bukhari and Muslim].

3 - It is reported in Sahihain (Bukhari and Muslim) from Ibn 'Abbas, he said: "I never saw the Prophet Muhammad (Blessings and peace of Allah be upon him) seeking to fast on a day more (preferable to him) than this day, (the day of 'Ashura) or this month, i.e. the month of Ramadan.
Imam al-Tirmizi narrated from Abu Qatadah that the Prophet Muhammad (Blessings and peace of Allah be upon him) said: "I hope from Allah that the fast on the day of 'Ashura atones for the sins of the preceding year."

Imam Ahmad narrated that "it atones the sins of two years, past and subsequent year".


4 - Imam Muslim narrated from Ibn Abbas, he said: "When the Messenger of Allah (Blessings and peace of Allah be upon him) fasted on the day of Ashura and commanded that it should be observed as a fast, they (his Companions) said to him: Messenger of Allah, it is a day which the Jews and Christians hold in high esteem. Thereupon, the Messenger of Allah (peace be upon him) said: When the next year comes, God willing, we would observe fast on the 9th . But the Messenger of Allah (Blessings and peace of Allah be upon him) died before the advent of the next year".

This is the guidance of the Prophet Muhammad (Blessings and peace of Allah be upon him) regarding to 'Ashura. His Companions and their followers went on this way. They have not distinguished this day by any practice except fasting.

But many acts done by some ignorant Muslims which "deform the face of Islam" have no evidence from Qur'an and Hadith. These acts include celebrating on this day, slapping one's face, tearing of one's clothes, using swords and blood-shedding. None of these acts have any authentic relevance to 'Ashura, but are among the innovations .

uling on fasting only on the day of 'Ashura

Shaykh ul-Islam said:

"Fasting on the day of 'Ashura is an expiation for a year, and it is not makruh to fast only that day ... " [Al-Fatawa al-Kubra].

In Tuhfat al-Muhtaj by Ibn Hajar al-Haytami, it says:

"There is nothing wrong with fasting only on 'Ashura."



Fasting on 'Ashura even if it is a Saturday or a Friday

At-Tahawi, may Allah have mercy on him, said:

"The Messenger of Allah, peace be upon him, allowed us to fast on 'Ashura and urged us to do so. He did not say that if it falls on a Saturday we should not fast. This is evidence that all days of the week are included in this. In our view – and Allah knows best – it could be the case that even if this is true (that it is not allowed to fast on Saturdays), it is so that we do not venerate this day and refrain from food, drink and intercourse, as the Jews do. As for the one who fasts on a Saturday without intending to venerate it, and does not do so because the Jews regard it as blessed, then this is not makruh ... " [Mushkil al-Athar]

The author of Al-Minhaj said:

"'It is disliked (makruh) to fast on a Friday alone ... ' But it is no longer makruh if you add another day to it, as mentioned in the sahih report to that effect. A person may fast on a Friday if it coincides with his habitual fast, or he is fasting in fulfilment of a vow, or he is making up an obligatory fast that he has missed, as was stated in a sahih report."

Al-Sharih said in Tuhfat al-Muhtaj:

"'If it coincides with his habitual fast' – i.e., such as if he fasts alternate days, and a day that he fasts happens to be a Friday. 'If he is fasting in fulfilment of a vow, etc.' – this also applies to fasting on days prescribed in Shari'ah, such as 'Ashura or 'Arafah."

Al-Bahuti, may Allah have mercy on him, said:

"It is makruh to deliberately single out a Saturday for fasting, because of the hadith of 'Abdullah ibn Bishr, who reported from his sister: 'Do not fast on Saturdays except in the case of obligatory fasts' [Reported by Ahmad with a jayyid isnad and by al-Hakim, who said it was according to the conditions of al-Bukhari], and because it is a day that is venerated by the Jews, so singling it out for fasting means being like them ... except when a Friday or Saturday coincides with a day when Muslims habitually fast, such as when it coincides with the day of 'Arafah or the day of 'Ashura, and a person has the habit of fasting on these days, in which case it is not makruh, because a person's habit carries some weight." [Kashshaf al-Qina']



What should be done if there is confusion about the beginning of the month?

Ahmad said:

"If there is confusion about the beginning of the month, one should fast for three days, to be sure of fasting on the ninth and tenth days." (Al-Mughni of Ibn Qudamah]

If a person does not know when Muharram began, and he wants to be sure of fasting on the tenth, he should assume that Dhul-Hijjah was thirty days – as is the usual rule – and should fast on the ninth and tenth. Whoever wants to be sure of fasting the ninth as well should fast the eight, ninth and tenth (then if Dhul-Hijjah was twenty-nine days, he can be sure of having fasted Tasu'a and 'Ashura).

But given that fasting on 'Ashura is mustahabb rather than wajib, people are not commanded to look for the crescent of the new moon of Muharram as they are to do in the case of Ramadhan and Shawwal