The observance of fasting on the day of `Ashura is rooted in profound historical and religious significance within Islam. Ibn ‘Abbas, a companion of the Prophet Muhammad (peace and blessings of Allah be upon him), recounts that upon the Prophet's arrival in Madeenah, he noticed the Jews fasting on `Ashura. This day marked the moment when Allah saved the Children of Israel from their enemies, prompting Moosa (Moses) to fast in gratitude. The Prophet Muhammad stated that Muslims have a greater claim to Moosa and thus, he fasted on that day and instructed his followers to do the same.
The practice of fasting on `Ashura predates Islam, with evidence suggesting that the Quraysh and other pre-Islamic communities observed this fast. The Prophet himself fasted on `Ashura in Makkah before his migration to Madeenah. However, upon migration, he sought to distinguish Muslims from Jews, who treated the day as a festival, by commanding Muslims to fast.
Initially, fasting on `Ashura was obligatory, but this was later abrogated in favor of the fasting during the month of Ramadaan. Despite this, fasting on `Ashura remains highly meritorious, with the Prophet expressing exceptional eagerness to fast on this day, hoping for the expiation of sins from the preceding year.
`Ashura falls on the tenth day of Muharram, the first month of the Islamic calendar, with Tasu`a being the ninth day. Scholars recommend fasting on both the ninth and tenth days to differentiate from Jewish practices and to ensure the fast is observed on the correct day due to potential uncertainties in moon sighting.
The wisdom behind fasting on Tasu`a, in addition to `Ashura, is multifaceted. It serves to distinguish Islamic practice from that of the Jews and Christians, to add an extra day of worship, and to safeguard against possible errors in lunar date determination. Shaykh al-Islam Ibn Taymiyah emphasized the importance of differing from the People of the Book in religious practices, particularly in the observance of `Ashura.
While fasting solely on the day of `Ashura is not considered objectionable, it is preferable to fast an additional day to align with the Prophet's intentions. Moreover, fasting on `Ashura is encouraged regardless of whether it coincides with a Saturday or Friday, as the Prophet did not specify any restrictions based on the day of the week.
In conclusion, fasting on `Ashura is a tradition with deep historical roots and significant spiritual rewards. It is a day to remember the trials of the past, to express gratitude for divine salvation, and to seek forgiveness for the year that has passed. As Muslims around the world observe this fast, they honor a practice that the Prophet Muhammad held in high esteem, continuing a legacy of devotion and piety.