أَخْبَرَنَا سَهْلُ بْنُ حَمَّادٍ ، حَدَّثَنَا شُعْبَةُ ، عَنْ أَبِي بِشْرٍ ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ ، عَنْ ابْنِ عَبَّاسٍ ، أَنَّهُ قَالَ : قَدِمَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ الْمَدِينَةَ ، وَالْيَهُودُ يَصُومُونَ يَوْمَ عَاشُورَاءَ، فَسَأَلَهُمْ، فَقَالُوا : هَذَا الْيَوْمُ الَّذِي ظَهَرَ فِيهِ مُوسَى عَلَى فِرْعَوْنَ.
فَقَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ :" أَنْتُمْ أَوْلَى بِمُوسَى فَصُومُوهُ "

Sahl bin Hammad told us, Shu’bah told us, on the authority of Abu Bishr, on the authority of Sa’id bin Jubayr, on the authority of Ibn Abbas, that he said: He presented The Messenger of God, may God bless him and grant him peace, was in Medina, and the Jews were fasting on the day of Ashura. He asked them, and they said: This is the day on which Moses appeared. On Pharaoh.
Then the Messenger of God, may God bless him and grant him peace, said: “You are more deserving of Moses, so fast on his behalf.”