Please could you reference this Hadith?
“I never saw Nabi (sallallahu ‘alayhi wa sallam) seeking to fast on a day more preferable to him than this day, the day of ‘Aashura…”
Imam Bukhari (rahimahullah) has recorded this Hadith in his Sahih on the authority of Sayyiduna ‘Abdullah ibn ‘Abbas (radiyallahu ‘anhuma).
(Sahih Bukhari, Hadith: 2006)
Also see here.
And Allah Ta’ala Knows best.
Answered by: Moulana Suhail Motala
Approved by: Moulana Muhammad Abasoomar