He said that when God’s messenger fasted on the day of ‘Ashura’ and commanded that it should be observed as a fast, he was told it was a day held in honour by Jews and Christians, and said, “If I am spared till next year I shall fast on the ninth.” Muslim transmitted it.
Hadith Referenceمشكوة المصابيح / كتاب الصوم / 2041
Hadith Gradingالألبانی:صَحِيح | زبیر علی زئی:صحيح
Hadith Takhrij´تحقيق و تخريج: محدث العصر حافظ زبير على زئي رحمه الله` «رواه مسلم (133. 134 / 1134)»