صحیح مسلم · Hadith 2643

Abdullah b. 'Umar (Allah be pleased with them) reported that (the Arabs of) pre-Islamic days used to observe fast on the day of Ashura and the Messenger of Allah ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ) observed it and the Muslims too (observed it) before fasting in Ramadan became obligatory. But when it became obligatory, the Messenger of Allah ( ‌صلی ‌اللہ ‌علیہ ‌وسلم ‌ ) said: 'Ashura is one of the days of Allah, so he who wished should observe fast and he who wished otherwise should abandon it.

Translated by Dr. Muhammad Muhsin Khan · Reviewed by Islamic University of Madinah · Published March 2020