Sahih Muslim Book - 13, Hadith - 2653

حَدَّثَنِى حَرْمَلَةُ بْنُ يَحْيَى أَخْبَرَنَا ابْنُ وَهْبٍ أَخْبَرَنِى يُونُسُ عَنِ ابْنِ شِهَابٍ أَخْبَرَنِى حُمَيْدُ بْنُ عَبْدِ الرَّحْمَنِ أَنَّهُ سَمِعَ مُعَاوِيَةَ بْنَ أَبِى سُفْيَانَ خَطِيبًا بِالْمَدِينَةِ - يَعْنِى فِى قَدْمَةٍ قَدِمَهَا - خَطَبَهُمْ يَوْمَ عَاشُورَاءَ فَقَالَ أَيْنَ عُلَمَاؤُكُمْ يَا أَهْلَ الْمَدِينَةِ سَمِعْتُ رَسُولَ اللَّهِ -صلى الله عليه وسلم- يَقُولُ لِهَذَا الْيَوْمِ « هَذَا يَوْمُ عَاشُورَاءَ وَلَمْ يَكْتُبِ اللَّهُ عَلَيْكُمْ صِيَامَهُ وَأَنَا صَائِمٌ فَمَنْ أَحَبَّ مِنْكُمْ أَنْ يَصُومَ فَلْيَصُمْ وَمَنْ أَحَبَّ أَنْ يُفْطِرَ فَلْيُفْطِرْ ».

Humaid bin Abdur Rahman narrated that he heard Muawiyah bin Abi Sufyan delivering a Khutbah in Al-Madinah - meaning, on jone jof his visits there - on the day of Ashura, in which he said: “Where are your scholars, O people of Al-Madinah? I heard the Messenger of Allah say concerning this day: ‘This is the day of Ashura and Allah has not enjoined you to fast (on this day) and I am fasting. So whoever among you wants to fast, let him do so, and whoever among you does not want to fast, let him not do so.”