Abdullah bin Abbas reported,

When the Messenger of Allah ﷺ arrived in Medina, the Jews were fasting on Ashura. He asked them about it, and they replied, "This is the day on which Musa triumphed over Pharaoh."The Prophet ﷺ said, "We have a greater claim to Musa than they do, so fast on this day."

Azami 12731

Sahih

عن ابن عباس قال

لما قدم رسول الله ﷺ المدينة، واليهود تصوم عاشوراء، فسألهم، فقالوا: هذا اليوم الذي ظهر فيه موسى على فرعون، فقال النبي ﷺ: نحن أولى بموسى منهم فصوموه.

الأعظمي 12731صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Tafsir of the great Quran
Chapter
Tafsir of Surah Taha
Section
His saying, "And We certainly revealed to Musa, 'Travel by night with My servants and strike for them a dry path through the sea. You will not fear being overtaken nor be afraid.' So Pharaoh pursued them with his soldiers, and there covered them from the sea that which covered them. And Pharaoh led his people astray and did not guide them."
Numbering
Jami al-Kamil 12731 (2nd edition)
Azami 12731