“The Messenger of Allah — may Allah’s peace and blessings be upon him — arrived in al-Madīnah and found the Jews fasting on the Day of ʿĀshūrāʾ. He said to them: ‘What is this day that you are fasting?’
They said: ‘This is a great day — on this day Allah saved Mūsā and his people, and drowned Pharaoh and his people. So Mūsā fasted it in gratitude (to Allah), and we fast it as well.’
The Messenger of Allah — may Allah’s peace and blessings be upon him — said: ‘We have more right and a closer claim to Mūsā than you.’
So the Messenger of Allah — may Allah’s peace and blessings be upon him — fasted on that day and commanded that it be fasted.”
Narrated by al-Bukhārī (no. 2004) and Muslim (no. 1130) — and this is his wording — from the ḥadīth of Ibn ʿAbbās – may Allah be pleased with him.
Brief Explanation of the Hadith
The Day of ʿĀshūrāʾ is the tenth day of the sacred month of Allah, al-Muḥarram. It is a great day which Allah has honored and distinguished with the virtue of fasting, for profound divine and legal wisdoms known to Him alone, Glorified and Exalted be He.
In this ḥadīth, Ibn ʿAbbās – may Allah be pleased with them both – relates that when the Prophet — may Allah’s peace and blessings be upon him — arrived in al-Madīnah, he found the Jews — in the second year after the Hijrah — fasting on the tenth day of al-Muḥarram. He asked them about the reason for their fasting, and they told him that it was a great day on which momentous events occurred that warranted its veneration.
For on that day, Allah saved Mūsā (peace be upon him) and his people, and drowned Pharaoh and his troops. Thereupon, Mūsā (peace be upon him) fasted that day in gratitude to Allah, the Exalted, and the Jews fasted it following the example of Mūsā (peace be upon him). At which point, the Messenger of Allah — may Allah’s peace and blessings be upon him — said: “We have more right and a closer claim to Mūsā than you.”
This was because the Prophet — may Allah’s peace and blessings be upon him — and Mūsā (peace be upon him) are joined in prophethood and messengership, in the fundamentals of religion and pure monotheism (tawḥīd), and in the bond of faithful brotherhood. So the Messenger of Allah — may Allah’s peace and blessings be upon him — fasted that day and commanded that it be fasted as an obligation. A group of scholars held this view based on the apparent meaning of the text, while others maintained that its fasting was recommended (mustahabb), interpreting the command to refrain as a form of emphasis.
Then, when the fast of the month of Ramaḍān was made obligatory, the obligation of fasting ʿĀshūrāʾ was abrogated and replaced with recommendation. Thus, whoever wishes to fast it may do so, and whoever wishes may abstain, and there is no disagreement among the scholars regarding the recommendation of fasting it.
In this ḥadīth is an indication of the legitimacy of worshipping Allah, Exalted be He, out of gratitude for His blessings — by performing acts of worship that are prescribed in the Sharīʿah, through which the servant manifests his thankfulness to Allah — without introducing into the religion anything that does not belong to it.