Sunan Abi Dawud 2841
سنن أبي داود#2841SahihNarrated 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
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautHasan Sahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 16:54