Ka'b al-Ahbar (may Allah have mercy on him) narrates: I said to Sayyiduna Umar bin al-Khattab (may Allah be pleased with him): "I certainly know a people who, if this verse had been revealed to them, would surely have paid attention to the day on which it was revealed and taken it as a festival (Eid)." Sayyiduna Umar (may Allah be pleased with him) asked: "Which verse is it?" He said: "This day I have perfected for you your religion" (to the end of the verse). Then Sayyiduna Umar (may Allah be pleased with him) said: "I certainly know on which day 'This day I have perfected for you your religion' was revealed: it was a Friday, and it was the Day of Arafah, and both of these are festival days for us."
No one narrated this hadith from Ishaq bin Qabisah (may Allah have mercy on him) except Ubadah bin Nusayy (may Allah have mercy on him), and no one from Ubadah (may Allah have mercy on him) except Raja' (may Allah have mercy on him); Zayd bin al-Hubab (may Allah have mercy on him) is alone in narrating it.
Hadith Referenceالمعجم الأوسط / باب الألف / 830
Hadith Takhrij«أخرجه البخاري فى «صحيحه» برقم: 45، 4407، 4606، 7268، ومسلم فى «صحيحه» برقم: 3017، وابن حبان فى «صحيحه» برقم: 185، والنسائي فى «المجتبى» برقم: 3002 / 1، 5027 / 3، والنسائي فى «السنن الكبرى» برقم: 3983، 11072، والترمذي فى «جامعه» برقم: 3043، والبيهقي فى «السنن الكبرى» برقم: 5704، 9573، 9574، وأحمد فى «مسنده» برقم: 193، 278، والحميدي فى «مسنده» برقم: 31، وعبد بن حميد فى «مسنده» برقم: 30، وابن حجر فى «المطالب العالية» برقم: 3591، والطحاوي فى «شرح مشكل الآثار» برقم: 2500، 2499، والطبراني فى «الأوسط» برقم: 3900»