‘Aashoora’ in Islam and previous religions, and refutation of the Raafidi claim that it is an innovation introduced by the Umayyads
Question

Is the day of 'Ashura on which we fast not the correct day? Because I read that the correct day is the tenth day of the month of Tishrei in the Hebrew calendar, and that the Umayyad caliphs are the ones who changed it to the tenth day of the month of Muharram. Tishrei is the first month of the Jewish calendar.
Praise be to Allah.-1-
The fast of ‘Aashoora’, which we observe on the tenth day of the month of Muharram, is the day on which Allah, may He be exalted, saved Moosa (peace be upon him), and it is the day on which some of the Jews in Madinah fasted because of that. It is also the day on which Allah commanded the Prophet (blessings and peace of Allah be upon him) to fast at first, then the obligation to do so was abrogated when fasting Ramadan was made obligatory, and fasting ‘Aashoora’ became mustahabb (encouraged but not obligatory). 
The claim that some of the Umayyad caliphs are the ones who put this day in Muharram is a Raafidi claim. It is one of the many lies on which their religion is based and it is part of their belief to attribute all kinds of evil to the Umayyad caliphs and their era. If the Umayyads had wanted to fabricate false hadiths and attribute them to Islam, they would have fabricated hadiths that made the day of ‘Aashoora’ an Eid or festival! and not a day of fasting on which a person refrains from eating, drinking and sex. Fasting is an act of worship in which one refrains from permissible things, and Eid is a celebration in which one partakes of those things. 
-2-
There is no doubt that the arrival of the Prophet (blessings and peace of Allah be upon him) in Madinah, when he migrated, occurred in Rabee‘ al-Awwal, not in Muharram. He saw some of the Jews fasting, and when he asked them about this fast of theirs, they said: It is the day on which Allah saved Moosa and those who were with him from drowning, so we fast on this day in gratitude to Allah. 
It was narrated from Ibn ‘Abbas (may Allah be pleased with him) that when the Prophet (blessings and peace of Allah be upon him) came to Madinah, he found them fasting on one day, i.e., ‘Aashoora’. They said: This is a great day; it is the day on which Allah saved Moosa and drowned the people of Pharaoh, so Moosa fasted in gratitude to Allah. He (the Prophet (blessings and peace of Allah be upon him)) said: “I am closer to Moosa than they are.” So he fasted on that day and issued instructions to fast on that day.
Narrated by al-Bukhaari, 3216 
When he saw the Jews doing that, was it when he first came to Madinah in Rabee‘ al-Awwal, or was it later on, in the month of Muharram? 
There are two scholarly views; the more correct view is that his seeing them, that discussion and that command to fast occurred in Muharram, i.e., in the second year after he (blessings and peace of Allah be upon him) arrived in Madinah, and from that we may conclude that the Jews followed the lunar calendar in commemorating that day. 
Ibn Qayyim al-Jawziyyah (may Allah have mercy on him) said: 
Some people were confused by this and said: The Messenger of Allah (blessings and peace of Allah be upon him) came to Madinah in the month of Rabee‘ al-Awwal, so how come Ibn ‘Abbas said that when he came to Madinah, he found the Jews fasting on the day of ‘Aashoora’? 
He (may Allah have mercy on him) said: 
With regard to the first issue, which is that when he came to Madinah, he found them fasting on the day of ‘Aashoora’, this does not indicate that on the day of his arrival he found them observing that fast. He arrived on a Monday, the twelfth of Rabee‘ al-Awwal, but the first he knew of that was in the second year after his arrival in Madinah, and it did not happen when he was in Makkah. This is if the people of the Book worked out the date for this fast according to the lunar calendar.
Zaad al-Ma‘aad fi Hadiy Khayr al-‘Ibaad, 2/66 
Al-Haafiz Ibn Hajar (may Allah have mercy on him) said: 
The apparent meaning of the report was problematic to some people, because it appears to mean that when the Prophet (blessings and peace of Allah be upon him) arrived in Madinah, he found the Jews fasting the day of ‘Aashoora’, but he arrived in Madinah in Rabee‘ al-Awwal. The answer to that is that what is meant is that his first knowing of that and asking about it happened after he came to Madinah; he had no knowledge of that before he came there. What the hadith implies is that the Prophet (blessings and peace of Allah be upon him) came to Madinah and stayed until the day of ‘Aashoora’, when he found the Jews fasting on that day.
Fath al-Baari, 4/247 
-3-
Was the calendar that the Jews used for that fast of theirs based on lunar or solar months? 
If we say that it was based on lunar months, as stated above, then there is no problem, because the tenth of Muharram does not change every year. But if we say that it was based on solar months, then there is a problem, because this day will change every year (in relation to the lunar calendar) and will not always coincide with the tenth day of Muharram. 
Ibn al-Qayyim (may Allah have mercy on him) mentioned this difference of opinion, and explained that he was of the view that their calendar was based on the solar months, so when the Prophet (blessings and peace of Allah be upon him) saw the Jews fasting on that day, it was in Rabee‘ al-Awwal when he first came to Madinah, and the date based on the solar calendar coincided with his arrival. With regard to the real day on which Allah saved Moosa, it was the tenth of Muharram, but because they followed a solar calendar, they got the day wrong. 
Ibn Qayyim al-Jawziyyah (may Allah have mercy on him) said: 
If they followed the solar calendar, there is no confusion about the meaning of the hadith, and the day on which Allah saved Moosa was the day of 'Ashura in Muharram. Thus the people of the Book worked it out according to a solar calendar, and that coincided with the Prophet’s arrival in Madinah in Rabee‘ al-Awwal. The fast observed by the people of the Book was worked out according to a solar calendar, whereas the Muslims’ fast is according to the lunar calendar, as is their pilgrimage and all important occasions that are obligatory or recommended. The Prophet (blessings and peace of Allah be upon him) said: “We are closer to Moosa than you.” Thus it becomes clear that the Muslims should have a greater reason to venerate that day and work out when it is, and that they (the Jews) got it wrong, because they were using a solar calendar, as the Christians got it wrong with regard to their fast, when they put it in a particular season of the year, with the result that it could coincide with any lunar month. 
Zaad al-Ma‘aad fi Hadiy Khayr al-‘Ibaad, 2/69, 70 
Al-Haafiz Ibn Hajr mentioned this possible interpretation, and refuted it, and he refuted Ibn al-Qayyim’s favouring of this view.  
He (may Allah have mercy on him) said: 
Some of the later scholars said: It may be that their fast was worked out according to the solar calendar, which does not rule out the possibility of 'Ashura occurring in Rabee‘ al-Awwal, which would resolve the problem (of understanding the hadith) altogether. This was stated by Ibn al-Qayyim in al-Hadiy, where he said: The fast observed by the people of the Book was worked out according to a solar calendar. But I say: What he claimed of the problem being resolved is strange, because it leads to another problem, which is that the Prophet (blessings and peace of Allah be upon him) instructed the Muslims to fast 'Ashura according to the lunar calendar, and it is known how the Muslims fasted 'Ashura in all eras: it was in Muharram and not in any other month. Yes, I found a report in at-Tabaraani with a jayyid isnaad from Zayd ibn Thaabit who said: The day of 'Ashura is not the day people say it is; rather it is the day on which the cover of the Ka‘bah replaced and the Abyssinians play with swords and other tools of war, and was not fixed in one (lunar) month. The people used to go to So and so, the Jew, and ask him when it was; when he died they came to Zayd ibn Thaabit and asked him. 
Based on this, the way to reconcile the reports is to say that it was originally like that (based on a solar calendar), then when the Prophet (blessings and peace of Allah be upon him) instructed the Muslims to fast 'Ashura, he based it on the shar‘i ruling, which is to base it on the lunar calendar, and the Muslims followed that. But with regard to the claim that the people of the Book based their fast on a solar calendar, that is subject to further discussion. The Jews base their fast on a lunar calendar, and this is what we have seen them do. It may be that among them were some who followed a solar calendar, but there are none who do that now, just as those of whom Allah has told us that they said that ‘Uzayr was a son of God no longer exist. Exalted be Allah far above that. 
Fath al-Baari, 7/267; see also 4/247 
Elsewhere in Fath al-Baari, al-Haafiz Ibn Hajar says, commenting on the report of at-Tabaraani:
I came across something similar in al-Athaar al-Qadeemah by Abu’r-Rayhaan al-Bayrooni, and what he said, in brief, was: the ignorant among the Jews base their fasts and festivals on astronomical calculations, so their year is solar, not lunar. I say: Hence they need someone who has knowledge of such calculations, so that they can rely on him for that purpose. 
Fath al-Baari, 4/247, 248 
With regard to the report of Zayd ibn Thaabit that was mentioned by al-Haafiz Ibn Hajar (may Allah have mercy on him), and to which he responded, al-Haafiz Ibn Rajab (may Allah have mercy on him) has discussed its isnaad and text. 
He (may Allah have mercy on him) said: This suggests that 'Ashura is not in Muharram; rather its date is worked out according to the solar calendar, as the people of the Book do, and this is contrary to the practice of the Muslims in earlier times. Ibn Abi’z-Zinnaad is not to be relied on in reports that are narrated only by him. He regarded the entire hadith as being from Zayd ibn Thaabit, and the latter part of it is not fit to be the words of Zayd, so perhaps that is the words of another narrator. And Allah knows best. 
Lataa’if al-Ma‘aarif, p. 53 
-4-
One may ask: how come the Prophet (blessings and peace of Allah be upon him) believe what the Jews said about the day of 'Ashura being the day on which Moosa and those who were with him were saved? This is what the Raafidis ask with evil ulterior motives, so as to cast aspersions on the hadiths which encourage fasting on the day of 'Ashura, and so as to support their claim that this is one of the innovations introduced by the Umayyads! 
Al-Maaziri (may Allah have mercy on him) said concerning this issue and the response to it: 
What the Jews say is not to be accepted (and taken as true), so it may be that the Prophet (blessings and peace of Allah be upon him) received revelation that confirmed what they said, or that he heard about that from many different sources, so that he concluded that it was true. End quote. 
This was quoted by an-Nawawi in Sharh Muslim, 8/11 
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said: 
Even though this fast was not originally intended to do the same as the people of the Book, his saying, “We are closer to Moosa than you” is a confirmation of the prescription to observe this the fast, and explaining to the Jews that what you do of expressing love for Moosa, we do too, and we are closer to Moosa than you. 
Iqtida’ as-Siraat al-Mustaqeem, p. 174 
-5-
It should be noted that the Prophet (blessings and peace of Allah be upon him) liked to do the same as the people of the Book in matters concerning which he had not received any (divine) instructions; this included the fast of 'Ashura. 
It was narrated from ‘Abdullah ibn ‘Abbas (may Allah be pleased with him) that the Prophet (blessings and peace of Allah be upon him) used to let his hair fall over his foreheads; the mushrikeen used to part their hair and the people of the Book used to let their hair fall over their foreheads, and the Prophet (sa) liked to do the same as the people of the Book in matters concerning which he had not received any (divine) instructions. Then (later on) the Prophet (sa) parted his hair.
Narrated by al-Bukhaari, 3728 
It is a sign of Imam al-Bukhaari’s understanding of the religion that he narrated this hadith after the two hadiths of Abu Moosa and Ibn ‘Abbas (may Allah be pleased with them) that speak of the fast of 'Ashura. 
Abu’l-‘Abbas al-Qurtubi (may Allah have mercy on him) said: 
The fact that the Messenger of Allah (blessings and peace of Allah be upon him) fasted it ('Ashura) may have come under the heading of doing the same as them (the people of the Book) in that regard, because that was a good deed. 
It may be said that Allah, may He be exalted, gave him permission to fast on that day, then when he came to Madinah, he found the Jews fasting on that day, so he asked them about what motivated them to observe that fast. They told him what Ibn ‘Abbas mentioned, that it was a great day, on which Allah saved Moosa and his people, and drowned Pharaoh and his people, so Moosa fasted that day in gratitude, so we fast it too. The Prophet (blessings and peace of Allah be upon him) said: “We have more right and are closer to Moosa than you.” So at that time he fasted this day in Madinah and issued instructions to fast on that day, i.e., he made it obligatory to fast it and confirmed his instructions, to such an extent that they would make little children fast as well. The Prophet (blessings and peace of Allah be upon him) adhered to that, as did his Companions, until the month of Ramadan was made obligatory and fasting the day of 'Ashura was abrogated. At that time he said: “Allah has not prescribed fasting this day for you.” Then he gave them the choice between fasting it or not fasting it, but the virtue attached to it remained in place, because he said “However I am fasting,” as it says in the hadith of Mu‘aawiyah. 
Based on that, the Prophet (blessings and peace of Allah be upon him) did not fast the day of 'Ashura in emulation of the Jews, because he used to fast it before he came to them and before he knew anything about them; rather what happened was that he made it obligatory, in hope of softening the Jews’ hearts and win them over to Islam, just as was the reason for facing towards their qiblah. That period was the time when the Prophet (blessings and peace of Allah be upon him) liked to do the same as the people of the Book in matters that he had not been forbidden to do so. 
Al-Mufhim lima Ashkala min Talkhees Kitaab Muslim, 3/191-192 
Al-Haafiz Ibn Hajar (may Allah have mercy on him) said: 
Whatever the case, he (blessings and peace of Allah be upon him) did not fast it in emulation of them – i.e., the Jews – because he used to fast it before that, and that was at the time when the Prophet (blessings and peace of Allah be upon him) liked to do the same as the people of the Book in matters that he had not been forbidden to do so.
Fath al-Baari, 4/248 
-6-
We have seen above from the comments of the scholars that which indicates that the day of 'Ashura was known to Quraysh and to the Prophet (blessings and peace of Allah be upon him) in Makkah, and they used to venerate it and indeed fast it. The Prophet (blessings and peace of Allah be upon him) fasted it with them, and on that day they used to put the new cover on the Ka‘bah. So how can anyone, after all this, falsely claim that 'Ashura is an Umayyad innovation at the time when it is clearly mentioned in the proven, saheeh hadiths?! 
It was narrated that ‘Aa’ishah (may Allah be pleased with her) said: Quraysh used to fast on 'Ashura during the Jaahiliyyah, and the Messenger of Allah (blessings and peace of Allah be upon him) used to fast on (that day) too. When he migrated to Madinah, he fasted this day and ordered that this fast be observed. When the month of Ramadaan was enjoined, he said: “Whoever wishes may fast on (this day) and whoever wishes may forsake it.”
Narrated by al-Bukhaari (1794); Muslim (1125). 
‘Abdullah ibn ‘Umar (may Allah be pleased with him) narrated that the people of the Jaahiliyyah used to fast on the day of 'Ashura, and the Messenger of Allah (blessings and peace of Allah be upon him) and the Muslims fasted it before Ramadaan was made obligatory. When the month of Ramadaan was made obligatory, the Messenger of Allah (blessings and peace of Allah be upon him) said: “ 'Ashura is one of the days of Allah, so whoever wishes may fast it and whoever wishes may omit it.” 
Narrated by Muslim (1126). 
We have quoted the hadith of Ibn ‘Umar here so as to refute the Raafidis and those who followed them in their ignorance, who claim that ‘Aa’ishah (may Allah be pleased with her) was the only one who narrated the report about the Prophet (blessings and peace of Allah be upon him) fasting 'Ashura in Makkah. 
Ibn ‘Abd al-Barr (may Allah have mercy on him) said: 
‘Abdullah ibn ‘Umar (may Allah be pleased with him) narrated from the Prophet (blessings and peace of Allah be upon him) a report similar to that of ‘Aa’ishah concerning this matter. It was also narrated by ‘Ubaydullah ibn ‘Umar and  Ayyoob, from Naafi‘, from Ibn ‘Umar that he said concerning the fast of 'Ashura: The Messenger of Allah (blessings and peace of Allah be upon him) fasted it and instructed (the people) to fast it. 
At-Tamheed lima fi’l-Muwatta’ min al-Ma‘aani wa’l-Asaaneed, 7/207 
An-Nawawi (may Allah have mercy on him) said: 
What we conclude from these hadiths is that during the Jaahiliyyah, the kuffaar of Quraysh and others, and the Jews, fasted on the day of 'Ashura. Islam confirmed fasting on this day, then the ruling on fasting it became less emphatic.
Sharh Muslim, 8/9, 10 
Abu’l-‘Abbas al-Qurtubi (may Allah have mercy on him) said: 
The words of ‘Aa’ishah (may Allah be pleased with her): “Quryash used to fast 'Ashura during the Jaahiliyyah,” indicate that fasting on this day was known to them to be prescribed and they were aware of its virtue. Perhaps they fasted on that day on the grounds that it was part of what was prescribed to Ibraaheem and Ismaa‘eel (blessings and peace of Allah be upon them), because they claimed to be following them and they attributed many of the rulings of Hajj and so on to them. 
Al-Mufhim lima Ashkala min Talkhees Kitaab Muslim, 3/190, 191 
For more information on the reasons why Quraysh fasted on that day, please see al-Mufassal fi Tareekh al-‘Arab qabl al-Islam, 11/339, 340 
-7-
Finally, what we have mentioned from the saheeh Sunnah about the virtues of 'Ashura, and the fact that fasting it expiates for the sins of a year, and that its date is fixed, on the tenth of Muharram – all of that is not unique to Ahl as-Sunnah. Rather it is also mentioned in the main reference book of the Raafidis! So how can this be reconciled with their claims that what we have are israa’eeliyyat (stories from Jewish sources), that were taken from the Jews or invented by the Umayyads?? 
(i)
It was narrated from Abu ‘Abdullah (peace be upon him) from his father that ‘Ali (peace be upon him) said: Fast 'Ashura in this manner, on the ninth and the tenth, for it expiates the sins of a year.
Narrated by at-Toosi in Tahdheeb al-Ahkaam, 4/299; al-Istibsaar, 2/134; by al-Fayd al-Kaashaani in al-Waafi, 7/13; by al-Hurr al-‘Aamili in Wasaa’il ash-Shi‘ah, 7/337; by al-Buroojardi in Jaami‘ Ahaadeeth ash-Shi‘ah, 9/474, 475. 
(ii)
It was narrated from Abu’l-Hasan (peace be upon him) that he said: The Messenger of Allah (blessings of Allah be upon him and his family) fasted the day of 'Ashura. 
Tahdheeb al-Ahkaam, 4/39; al-Istibsaar, 2/134; al-Waafi, 7/13; Wasaa’il ash-Shi‘ah, 7/337; also in Jaami‘ Ahaadeeth ash-Shi‘ah, 9/475 
(iii)
It was narrated from Ja‘far, from his father (peace be upon him) that he said: Fasting the day of 'Ashura is an expiation for a year. 
Tahdheeb al-Ahkaam,4/300; al-Istibsaar, 2/134; Jaami‘ Ahaadeeth ash-Shi‘ah, 9/475; al-Hadaa’iq an-Naadirah, 13/371; al-Waafi by al-Kaashaani,7/13; al-Hurr al-‘Aamili in Wasaa’il ash-Shi‘ah, 7/337 
(iv)
It was narrated that ‘Ali (may Allah be pleased with him) said: Fast the day of 'Ashura, the ninth and the tenth to be on the safe side, because that is expiation for the past year. If one of you did not know about it before he ate, then let him fast for the rest of the day. 
This report was narrated by the Shi‘i hadith scholar Husayn an-Noori at-Tabrusi in Mustadrak al-Wasaa’il, 1/594; and by al-Buroojardi in Ahaadeeth ash-Shi‘ah, 9/475. 
(v)
It was narrated that Ibn ‘Abbas (may Allah be pleased with him) said: When you see the new moon of Muharram, then count (the days), and when the ninth day comes, then fast. I – that is, the narrator – said: Is that how Muhammad (peace be upon him and his family) used to fast? He said: Yes. 
This report was narrated by the Shi‘i Radiy ad-Deen Abu’l-Qaasim ‘Ali ibn Moosa ibn Ja‘far ibn Tawoos in his book Iqbaal al-A‘maal, p. 554; and by al-Hurr al-‘Aamili in Wasaa’il ash-Shi‘ah, 7/347; and by an-Noori at-Tabrusi in Mustadrak al-Wasaa’il, 1/594; and in Jaami‘ Ahaadeeth ash-Shi‘ah, 9/475. 
We have quoted these reports and their sources from the book Man qatala al-Husayn (radiy Allah ‘andhu)? by ‘Abdullah ibn ‘Abd al-‘Azeez. 
And Allah knows best.