Sahih al-Bukhari 1990
صحيح البخاري#1990Sahihحَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، أَخْبَرَنَا مَالِكٌ، عَنِ ابْنِ شِهَابٍ، عَنْ أَبِي عُبَيْدٍ، مَوْلَى ابْنِ أَزْهَرَ قَالَ شَهِدْتُ الْعِيدَ مَعَ عُمَرَ بْنِ الْخَطَّابِ ـ رضى الله عنه ـ فَقَالَ هَذَانِ يَوْمَانِ نَهَى رَسُولُ اللَّهِ صلى الله عليه وسلم عَنْ صِيَامِهِمَا يَوْمُ فِطْرِكُمْ مِنْ صِيَامِكُمْ، وَالْيَوْمُ الآخَرُ تَأْكُلُونَ فِيهِ مِنْ نُسُكِكُمْ. قَالَ أَبُو عَبْد اللَّهِ قَالَ ابْنُ عُيَيْنَةَ مَنْ قَالَ مَوْلَى ابْنِ أَزْهَرَ فَقَدْ أَصَابَ وَمَنْ قَالَ مَوْلَى عَبْدِ الرَّحْمَنِ بْنِ عَوْفٍ فَقَدْ أَصَابَ
Narrated Abu `Ubaid:(the slave of Ibn Azhar) I witnessed the `Id with `Umar bin Al-Khattab who said, Allah's Messenger (ﷺ) has forbidden people to fast on the day on which you break fasting (the fasts of Ramadan) and the day on which you eat the meat of your sacrifices (the first day of `Id ul Fitr and `Id ul-Adha)
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 30:97