We have numerous reports from many eminent companions including the Prophet’s wife Aishah, Abd Allah b. Mas’ud, Abd Allah b. Umar, Jabir b. Abd Allah and Qays b. Sa’d b. Ubadah stating that the Prophet (peace be upon him) used to insist on fasting the tenth of Muharram without fail. It was before Allah enjoined the fasting of Ramadan. We also learn from Aishah as well as others that it was a practice the Prophet (peace be upon him) continued before Hijrah as the Quraysh since pagan times used to fast.

Here are the exact words of Aishah: “The Quraysh in jahiliyyah times used to fast the tenth of Muharram; later the Prophet (peace be upon him) ordered us to fast it until Allah declared the fasting of Ramadan as obligatory whence the Prophet (peace be upon him) told us, “Whoever chooses to fast it (voluntarily) he or she may do so; whoever does not want to fast they are also free to do so.” (Reports by Bukhari and others)

Other companions (mentioned above) have also confirmed the statement of Aishah (Allah be pleased with her and other companions).

In conclusion, Muharram fasting was a practice continued from Jahiliyyah times by the Quraysh, and the Prophet (peace be upon him) ordered Muslims to follow it as an obligatory until Ramadan fasting was made mandatory, which occurred in the second year of Hijrah.

From then onward, the Prophet (peace be upon him) lifted the obligation and declared the fasting of the tenth of Muharram as an optional, voluntary act.