(20) باب أَىُّ يَوْمٍ يُصَامُ فِي عَاشُورَاءَ
Hakam b. 'Araj reported:
I asked Ibn Abbas (Allah be pleased with them) as he was reclining using his cloak as a pillow near Zamzam about fasting on 'Ashura. The rest of the hadith is the same.
Reference: Sahih Muslim 1133 b
In-book reference: Book 13, Hadith 171
USC-MSA web (English) reference(deprecated numbering scheme): Book 6, Hadith 2527