Volume 3, Book 31, Number 222:
Narrated Ibn ‘Abbas:
The Prophet came to Medina and saw the Jews fasting on the day of Ashura. He asked them about
that. They replied, “This is a good day, the day on which Allah rescued Bani Israel from their enemy.
Volume 3 – 454 / 1700
SAHIH BUKHARI VOLUME 3 > BOOK 31: FASTING
So, Moses fasted this day.” The Prophet said, “We have more claim over Moses than you.” So, the
Prophet fasted on that day and ordered (the Muslims) to fast (on that day).