“The Messenger of Allah (ﷺ) used to fast ‘Ashura’, and he ordered (others) to fast it too.”
Sunan Ibn Majah Book 7, Hadith 96
← Previous Hadith “I entered upon Abu Hurairah in his house and asked him about fasting the Day of ‘Arafah at ‘Arafat. Abu Hurairah said: ‘The Messenger of Allah (ﷺ) forbade fasting the Day of ‘Arafah at ‘Arafat.’”

Sunan Ibn Majah Book 7, Hadith 95 Next Hadith → “The Prophet (ﷺ) came to Al- Madinah, and he found the Jews observing a fast. He said: ‘What is this?’ They said: ‘This is the day when Allah saved Musa and drowned Pharaoh, so Musa fasted this day in gratitude.’ The Messenger of Allah (ﷺ) said: ‘We have more right to Musa than you do.’ So he fasted (that day) and enjoined (others) to fast it also.’”

Sunan Ibn Majah Book 7, Hadith 97