It is narrated from Sayyiduna Abdullah bin Badr al-Juhani (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said to them one day: "This is the day of Ashura, so fast it." A man from Banu Amr bin Awf stood up and said: "O Messenger of Allah, I left my people in such a state that some of them are fasting and some of them are not fasting." The Prophet (peace and blessings be upon him) said: "Go to them; whoever of them is not fasting should refrain from eating and drinking (for the rest of the day), and whoever is fasting should complete his fast."
Imam al-Tabarani (may Allah have mercy on him) said: "No one narrated this hadith from Yahya bin Abi Kathir (may Allah have mercy on him) except Mu'awiyah bin Sallam (may Allah have mercy on him), and it is narrated from Abdullah bin Badr (may Allah be pleased with him) only with this chain."
Hadith Referenceالمعجم الأوسط / باب الميم / 5683
Hadith Gradingمحدثین:إسناده صحيح
Hadith Takhrij«قال ابن حجر: هذا إسناد صحيح «الإصابة في تمييز الصحابة، ج 6، ص 32»» «أخرجه الضياء المقدسي فى «الأحاديث المختارة» برقم: 16، وأحمد فى «مسنده» برقم: 28294»