Sahih Muslim

Sahih Muslim 1130 b

Fasting on the day of Ashura'
Arabic hadith text
وَحَدَّثَنَاهُ ابْنُ بَشَّارٍ، وَأَبُو بَكْرِ بْنُ نَافِعٍ جَمِيعًا عَنْ مُحَمَّدِ بْنِ جَعْفَرٍ، عَنْ شُعْبَةَ، عَنْ أَبِي بِشْرٍ، بِهَذَا الإِسْنَادِ وَقَالَ فَسَأَلَهُمْ عَنْ ذَلِكَ
Translation

This hadith has been narrated by Ibn Bishr with the same chain of transmitters (but with a slight variation) that he (the Holy Prophet) inquired of them (Jews) about it (fasting on the day of 'Ashura).