Muharram originates from Yom kippur
Muharram was originally a Jewish festival. It is a copy and paste of Jewish Yom Kippur.
According to an authentic Bukhari Hadith, the Islamic Prophet Muhammad found that Jews were observing Ashura. He asked them about its significance Jews told Muhammad that it is day when Jews were delivered out of bondage from Egypt by Biblical prophet Moses.
Jesus observed it out of gratitude. Thereafter, Muhammad ordered Muslims to observe Ashura. The association with Karbala legend was a later development.
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