It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that a man asked the Prophet (peace and blessings be upon him) about fasting, and he (peace and blessings be upon him) said: "Keep the fasts of the White Days (the days of the bright moonlit nights), that is, three days of every month."
Imam al-Tabarani (may Allah have mercy on him) said: "This hadith was narrated from Badr bin al-Khalil only by Isa bin Yunus; Sulayman bin Dawud is alone in narrating it."
Hadith Referenceالمعجم الأوسط / باب الميم / 8282
Hadith Gradingمحدثین:رجاله ثقات
Hadith Takhrij«قال الهيثمي: رجاله ثقات «مجمع الزوائد ومنبع الفوائد، ج 3، ص 196»» «أخرجه البزار فى «مسنده» برقم: 5402، والطبراني فى «الكبير» برقم: 13924»