Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates that when the Messenger of Allah (peace and blessings be upon him) fasted on the day of Ashura, he ordered that it be fasted. They said: O Messenger of Allah (peace and blessings be upon him)! This is a day that the Jews and the Christians venerate. The Messenger of Allah (peace and blessings be upon him) said: "When the next year comes, we will, if Allah wills, also fast on the 9th." The narrator says: The next year had not yet come when he (peace and blessings be upon him) passed away.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8401
Abdullah bin Abbas (may Allah be pleased with them both) narrates that the Messenger of Allah (peace and blessings be upon him) said: "If I remain safe until next year, I will certainly fast on the 9th."
(Ahmad bin Yunus narrates from Ibn Abi Dhi'b that in the text he (peace and blessings be upon him) said: "If I live, if Allah wills, I will also fast on the 9th, fearing that the day of Ashura might be missed.")
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8402
Al-Hakam bin al-A'raj (may Allah have mercy on him) narrates: I went to Abdullah bin Abbas (may Allah be pleased with them both) and he was reclining on his cloak as a pillow near Zamzam. I sat with him, and he was an excellent companion. I said: Tell me about the day of Ashura. He sat up straight and then said: "About which aspect of it are you asking?" I said: About its fasting: which day should we fast? He said: "When you see the new moon of Muharram, count (the days), and when you wake on its 9th, wake up fasting." He says: I said: Is this how Muhammad (peace and blessings be upon him) used to fast? He said: "Yes."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8403
Dawud bin Ali (may Allah have mercy on him) narrates from his father, from his grandfather (may Allah be pleased with him), that the Messenger of Allah (peace and blessings be upon him) said: "If I remain, I will order fasting a day before or a day after the day of Ashura."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8405
Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates that the Messenger of Allah (peace and blessings be upon him) said: "Fast on the day of Ashura and differ from the Jews: fast one day before it or one day after it."
(In the narration of Ibn Abdan, he (peace and blessings be upon him) said: "Fast one day before it and one day after it.")
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصيام / 8406