there seems to be some misconceptions amongst the shi’a about the notion of fasting on the day of ‘Ashura, and that’s understandable as there is a difference of opinion amongst the scholars too, but here is an important clarification:

there are authenticated narrations found in Shi’a primary sources which recommend fasting on the day of Ashura (this may come as a surprise for many of us) - here are some:

HOWEVER: Our issue with the propagation of the fasting on this day by the Sunni sect is the notion that it is a joyous occasion because it supposedly marks the day which God saved Prophet Moses ع and drowned Fir’awn

I won’t go into the hadith analysis - but this hadith is believed by Shi’a to be a fabrication that was forged by the Umayyids to divert from the need to commemorate the tragedy of Karbala

If you’re interested for proof for this, DM me

In Shia hadith corpus, yes there are narrations encouraging fasting - but absolutely no narrations indicating that it is a joyous occasion. Neither is there any Islamic basis which validates equating Fasting to happiness.

as Such, some of our most prominent scholars have ruled in favour of fasting on the day, but with the intention of mourning.

Sayed al-Khoei says in Al-Mustanad Fi Sharh al-Urwah al-Wuthqah, volume 12, in the chapter of Fasting:

“rather it is permissible and recommended [to fast on ‘Ashura] especially [if done] mournfully according to what you know [of Karbala] with nothing else added to it”

Classical scholarly giant Sheikh al-Tusi also supports the view that: “the Fast of the Day of Ashura is to be observed out of calamity and grief”

al-Mabsut Fi Fiqh al-Imamiyya (1/282)

However: yes, there is an apparent contradiction in our hadith corpus in that there are also narrations discouraging the fasting on the day of Ashura - scholars have reconciled between the two sets of narrations in various ways:

• Sayed al-Khoei says the narrations that prohibit [fasting on Ashura] “are not authentic whatsoever” and are all weak - as such he has taken the position mentioned above of recommendation with the intention of mourning - and prohibited fasting with a joyous intent

• Sayed Fadhlallah also supports the ruling of Sayed al-Khoei

• Sayed al-Sistani says:

Fasting is not forbidden, rather it is disliked in the sense that it is less rewarding than simply holding it in sorrow until after the Asr prayer and then breaking the fast at that time with a drink of water

I believe amongst the scholars who Prohibit it’s fasting plainly without stipulation of conditions is Sayed Khamenai

and God knows best