Sunan Abi Dawud Fasting (Kitab Al-Siyam) al-Hakam bin 'Abdullah al-A'raj الحكم بن عبد الله بن إسحاق الأعرج Hajb bin 'Umar حاجب بن عمر Masdad bin Masrhad مسدد بن مسرهد بن مسربل Yahya bin Sa'id bin Farroukh al-Qatan يحيى بن سعيد بن فروخ القطان Sahih When the Prophet (ﷺ) on the day of ‘Ashurah and commanded us to fast on it, they (i.e. Companions) said: Messenger of Allah, this is a day which is considered great by Jews and Christians ? The Messenger of Allah (ﷺ) said: When the next year comes, we shall fast on the 9th of Muharram. But the next year the Messenger of Allah (ﷺ) breathed his last. https://parallelquran.com/hadith/sunan-abi-dawud-2445/ Jami' al-Tirmidhi The Book on Fasting Abu Karayb, Muhammad bin al-'Ala' محمد بن العلاء - أبو كريب al-Hakam bin 'Abdullah al-A'raj الحكم بن عبد الله بن إسحاق الأعرج Hajb bin 'Umar حاجب بن عمر Hanad bin al-Sari bin Mus'ab هناد بن السري بن مصعب Waki' bin al-Jarrah وكيع بن الجراح “I met up with Ibn Abbas while he was reclining on his Rida at the Zamzam (well). So I said: ‘Inform me about the Day of Ashura. On which day is it fasted?’ He said: ‘When you see the crescent of Al-Muharram, then count, then fast on the morning of the ninth day.'” He said: ‘I said: Is this how Muhammad fasted it?’ He said: ‘Yes.'” https://parallelquran.com/hadith/jami-al-tirmidhi-754/