The Book of Fasting (Kitab Al-Sawm)

Muslim :: Book 6 : Hadith 2515

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 (may peace be upon him) 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.

Source materials are from the University of Southern California MSA site
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