Lady Aisha (may Allah be pleased with her) says: The Messenger of Allah (peace and blessings be upon him) used to fast on the Day of Ashura during the Age of Ignorance, and the Quraysh also used to fast on this day during the Age of Ignorance. When the Noble Prophet (peace and blessings be upon him) came to Madinah, he also fasted on this day there and ordered the people to fast on this day as well. But when the fasting of the month of Ramadan was made obligatory, those fasts became obligatory and the fasting of the Day of Ashura was abandoned.

. (Second chain) There is a similar hadith, except that it states: When the command for the obligation of fasting in the month of Ramadan was revealed, the Prophet (peace and blessings be upon him) used to fast in it and abandoned fasting on the Day of Ashura. Now, whoever wishes may fast on that day, and whoever wishes may leave it.

Abdur Rahman bin Yazid says: Ash'ath bin Qais went to Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) on the day of Ashura, while he was eating food. He said: Abu Muhammad! Come near to eat food. Ash'ath said: Is today not the day of Ashura? He said: Do you know what Ashura is? The Messenger of Allah (peace and blessings be upon him) used to fast on this day before the obligation of Ramadan was revealed. When the command of the month of Ramadan was revealed, the fast of this day was abandoned.

Sayyiduna Abdullah bin Umar (may Allah be pleased with him) said regarding the Day of Ashura: The Messenger of Allah (peace and blessings be upon him) himself fasted on this day and also ordered fasting on it, but when the month of Ramadan was made obligatory, fasting on this day was abandoned. Thus, Sayyiduna Ibn Umar (may Allah be pleased with him) would not fast on this day, except if it coincided with a day on which he would customarily fast.

Sayyiduna Abdullah bin Umar (may Allah be pleased with him) says: The people of the Age of Ignorance used to fast on the Day of Ashura, but when the command for the obligation of the month of Ramadan was revealed, the Messenger of Allah (peace and blessings be upon him) was asked about this fast. He (peace and blessings be upon him) said: This is one of the days of Allah; whoever wishes may fast on it, and whoever wishes may leave it.

It is narrated from Sayyiduna Jabir bin Samurah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him and his family) used to command us to fast on the Day of Ashura, encourage us to do so, and when this day approached, he would also draw our attention to it. But when the fasting of the month of Ramadan was made obligatory, he (peace and blessings be upon him and his family) neither commanded us regarding it, nor forbade us from it, nor drew our attention to the arrival of this day.

It is narrated from Sayyiduna Qais bin Sa'd bin Ubadah that the Noble Prophet (peace and blessings be upon him) commanded us to fast on the Day of Ashura before the fasting of the month of Ramadan was made obligatory. When the fasting of Ramadan was made obligatory, he (peace and blessings be upon him) neither commanded it nor forbade it, but we continue to fast on that day.

Humaid bin Abdur Rahman says that Sayyiduna Muawiyah bin Abi Sufyan (may Allah be pleased with him) delivered a sermon in Madinah Munawwarah and said: O people of Madinah! Where are your scholars? I have heard the Messenger of Allah (peace and blessings be upon him) say: This is the day of Ashura, fasting on this day has not been made obligatory upon us, so whoever among you wishes to fast on this day may do so, however, I am fasting. Then the people also fasted.