حَدَّثَنَا زُهَيْرُ بْنُ حَرْبٍ، حَدَّثَنَا جَرِيرٌ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ، - رضى الله عنها - قَالَتْ كَانَتْ قُرَيْشٌ تَصُومُ عَاشُورَاءَ فِي الْجَاهِلِيَّةِ وَكَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَصُومُهُ فَلَمَّا هَاجَرَ إِلَى الْمَدِينَةِ صَامَهُ وَأَمَرَ بِصِيَامِهِ فَلَمَّا فُرِضَ شَهْرُ رَمَضَانَ قَالَ ‏"‏ مَنْ شَاءَ صَامَهُ وَمَنْ شَاءَ تَرَكَهُ ‏"‏ ‏.‏

Abd al-Rahman reported that he heard Mu'awiya b. Abu Sufyan delivering a sermon in Medina. i. e. when he came there (for Hajj). He delivered a sermon on the day of 'Ashura and said

People of Medina, where are your scholars? I heard the Messenger of Allah (ﷺ) say on this very day: It is the day of 'Ashura. Allah has not made fasting on This day obligatory for you but I am fasting. He who likes to observe fast among you should do so, and he who likes not to observe it may not observe it.