عَنْ قَيْسِ بْنِ سَعْدِ بْنِ عُبَادَةَ رَضِيَ اللَّهُ عَنْهُ قَالَ: أَمَرَنَا النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ أَنْ نَصُومَ عَاشُورَاءَ قَبْلَ أَنْ يَنْزِلَ رَمَضَانُ فَلَمَّا نَزَلَ رَمَضَانُ لَمْ يَأْمُرْنَا وَلَمْ يَنْهَنَا وَنَحْنُ نَفْعَلُهُ
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.