Sayyiduna Yunus bin Shaddad (may Allah be pleased with him) narrates: the Prophet (peace and blessings be upon him) forbade fasting on the Days of Tashriq.
Abdullah bin Ahmad and al-Bazzar recorded it. He (al-Bazzar) said: It is not known that Yunus narrated with a chain any hadith other than this one. Its chain contains a narrator, Sa'id bin Bashir, who is thiqah (trustworthy), but he suffered from confusion (ikhtilat) in his memory.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصيام / 5236