FASTING ON THE 10TH DAY OF MUHARRAM H 1277 "The Messenger of Allah, praise and peace be upon him, fasted on the tenth day of Muharram and exhorted that it should be observed as a fast." R 1277 Bukhari and Muslim with a chain up to ibn Abbas who related that the Messenger of Allah, praise and peace be upon him, said this.
1251- وعن ابن عباس رضي الله عنهما : أنَّ رسولَ الله صلى الله عليه وآله وسلم صَامَ يَومَ عاشوراءَ وَأمَرَ بِصِيامِهِ . متفقٌ عَلَيْهِ .