(19) باب صَوْمِ يَوْمِ عَاشُورَاءَ
Abu Musa (Allah be pleased with him) reported:
The day of 'Ashura was one which the Jews respected and they treated it as Id. The Messenger of Allah (ﷺ) said: You also observe fast on this day.
Reference: Sahih Muslim 1131 a
In-book reference: Book 13, Hadith 166
USC-MSA web (English) reference(deprecated numbering scheme): Book 6, Hadith 2522