Abdul Rahman bin Yazid said: When al-Ash'ath bin Qais entered the house of 'Abdullah he was having his breakfast. He ('Abdullah bin 'Umar (RA) said: Abu Muhammad (al-Asha'th), came near to the breakfast. Thereupon he said: Is not today the Day of 'Ashura? He ('Abdul Rahman) said: Do you know what the Day of 'Ashura is? He said: What is it? He said: It is a day on which the Messenger of Allah ( صلی اللہ علیہ وسلم ) used To observe fast before the (fasting) in the month of Ramadan became obligatory. But when it became obligatory the (fasting of 'Ashura) was abandoned (as compulsory). Abu Kuraib said: He (the Holy Prophet ( صلی اللہ علیہ وسلم ) abandoned it.