Could you please tell me about ‘Fasting on the day of ‘Ᾱshura in Muḥaram’? I have heard that the day is observed as an important day by both Shia and Sunni Muslims but for different reasons.
Jazākumullāhu Khayran/ Thank you for your question.
May you be blessed for your concern regarding religion.
The Prophetic ḥadīth indicates the reason for fasting on the 10th of Muḥarram, is to be thankful and express appreciation to Allāh, just as the Prophet Mūsa (peace and blessings upon him) was to Allāh for having being saved from the tyranny of Fir‘aun (the Pharaoh).
Looking at the Qur‘ānic verses and prophetic reports, I did not find any other reason for the fasting of Muḥarram.
Ibn ‘Abbās (may Allāh be please with him) narrates that the Prophet (peace and blessings upon him) came to Madīnah and found the Jews fasting on the day of Ᾱshūrah (10th of Muḥarram). Hence the Prophet (peace and blessings upon him) inquired of them, “What is (the significance of) this day on which you fast?” They replied, “This is a great day. On this day Allāh saved Mūsa (peace and blessings upon him) and his people, and drowned Fir’aun and his nation. Thus, Mūsa (peace and blessings upon him) fasted on this day as a token of thanksgiving, therefore we too fast on this day.” The Messenger of Allāh said, “We are more worthy of Mūsa (peace and blessings upon him) and nearer to him than you.” Thereafter, the Prophet (peace and blessings upon him) fasted on this day and ordered (his Companions) that a fast be kept on this day.” (Muslim)
And Allāh Knows Best