Abu al-Kawsaj, who was a freed slave of the family of Abu Farwah, narrates (or he composed this verse): "Do you think that, on the day you reviled me in the market, your father was al-Harith bin Hisham?"
Al-Tabarani recorded it; I do not know Ibn al-Kawsaj.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأدب / 13357
Hadith Gradingمحدثین:إسنادہ ضعیف
Hadith Takhrij«اخرجه الطبراني فى المعجم الكبير (3341)»