Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī

أَبُو الْمِنْهَالِ، عَنِ ابْنِ عَبَّاسٍ

tabarani:11266 – [Chain 1] al-ʿAbbās b. al-Faḍl al-Asfāṭī > ʿAbd al-Raḥman b. al-Mubārak al-ʿAyshī [Chain 2] Mūsá b. Hārūn > Dāwud b. ʿAmr al-Ḍabbī > Muslim b. Khālid al-Zanjī > Ismāʿīl b. Umayyah > Abū al-Minhāl > Ibn ʿAbbās > Dhukir Lilnnabī ﷺ > Yahūd Yaṣūmūn Yawm ʿĀshūrāʾ

[Machine] The Prophet ﷺ was informed that the Jews used to fast on the day of Ashura. He ﷺ said, "If we live, we will oppose them and fast on the ninth day."  

الطبراني:١١٢٦٦ – حَدَّثَنَا الْعَبَّاسُ بْنُ الْفَضْلِ الْأَسْفَاطِيُّ ثنا عَبْدُ الرَّحْمَنِ بْنُ الْمُبَارَكِ الْعَيْشِيُّ ح وَحَدَّثَنَا مُوسَى بْنُ هَارُونَ ثنا دَاوُدُ بْنُ عَمْرٍو الضَّبِّيُّ قَالَا ثنا مُسْلِمُ بْنُ خَالِدٍ الزَّنْجِيُّ عَنْ إِسْمَاعِيلَ بْنِ أُمَيَّةَ عَنْ أَبِي الْمِنْهَالِ عَنِ ابْنِ عَبَّاسٍ قَالَ

ذُكِرَ لِلنَّبِيِّ ﷺ أَنَّ يَهُودَ يَصُومُونَ يَوْمَ عَاشُورَاءَ فَقَالَ النَّبِيُّ ﷺ «إِنْ عِشْنا خالَفْنَاهُمْ وَصُمْنَا الْيَوْمَ التَّاسِعَ»  

See similar narrations below:

Collected by Suyūṭī