Sunan Abi Dawud 2841
سنن أبي داود#2841Sahihحَدَّثَنَا أَبُو مَعْمَرٍ عَبْدُ اللَّهِ بْنُ عَمْرٍو، حَدَّثَنَا عَبْدُ الْوَارِثِ، حَدَّثَنَا أَيُّوبُ، عَنْ عِكْرِمَةَ، عَنِ ابْنِ عَبَّاسٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم عَقَّ عَنِ الْحَسَنِ وَالْحُسَيْنِ كَبْشًا كَبْشًا .
Narrated Abdullah ibn Abbas: The Messenger of Allah (ﷺ) sacrificed a ram for both al-Hasan and al-Husayn each (Allah be pleased with them)
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:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautHasan Sahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 16:54