English translation
3942. Narrated Abū Mūsā رضي الله عنه. When the Prophet ﷺ arrived at Al-Madina, he noticed that some people among the Jews used to respect ‘Āshūrā’ (i.e., 10th of Muḥarram) and observe fast on it. The Prophet ﷺ then said, “We have more right to observe fast on this day,” and ordered that fasting should be observed on it. [Later on the fasting on the day of ‘Āshūrā’ was optional.] [See Vol.3, Hadith No. 2002]
