Sahih al-Bukhari 5571
Sahih al-Bukhari · Book 73: Al-Adha Festival Sacrifice (Adaahi) · What may be eaten of the meat of sacrifices and what may be taken as journey food
Narrated Abu `Ubaid:
حَدَّثَنَا حِبَّانُ بْنُ مُوسَى ، أَخْبَرَنَا عَبْدُ اللَّهِ ، قَالَ أَخْبَرَنِي يُونُسُ ، عَنِ الزُّهْرِيِّ ، قَالَ حَدَّثَنِي أَبُو عُبَيْدٍ ، مَوْلَى ابْنِ أَزْهَرَ أَنَّهُ شَهِدَ الْعِيدَ يَوْمَ الأَضْحَى مَعَ عُمَرَ بْنِ الْخَطَّابِ ـ رضى الله عنه ـ فَصَلَّى قَبْلَ الْخُطْبَةِ، ثُمَّ خَطَبَ النَّاسَ فَقَالَ يَا أَيُّهَا النَّاسُ إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَدْ نَهَاكُمْ عَنْ صِيَامِ هَذَيْنِ الْعِيدَيْنِ، أَمَّا أَحَدُهُمَا فَيَوْمُ فِطْرِكُمْ مِنْ صِيَامِكُمْ وَأَمَّا الآخَرُ فَيَوْمٌ تَأْكُلُونَ نُسُكَكُمْ.
the freed slave of Ibn Azhar that he witnessed the Day of `Id-al-Adha with `Umar bin Al-Khattab. `Umar offered the `Id prayer before the sermon and then delivered the sermon before the people, saying, "O people! Allah's Messenger (ﷺ) has forbidden you to fast (on the first day of) each of these two 'Ida, for one of them is the Day of breaking your fast, and the other is the one, on which you eat the meat of your sacrifices."