The Messenger of Allah ﷺ said, "When you see those who insult my companions, say, 'May the curse of Allah be upon the worst of you.'"
حدثنا أبو بكر محمد بن نافع حدثنا النضر بن حماد حدثنا سيف بن عمر عن عبيد الله بن عمر عن نافع
قال رسول الله ﷺ إذا رأيتم الذين يسبون أصحابي فقولوا لعنة الله على شركم
No references are available.
Takhrij, its chain is daif. Mizzi related it in Tahzib Kamal 8/251, through the hadith of Nadr, transmitted by him.Nadr bin Hammad is daif (Taqrib), and Sayf bin Umar is daif in hadith and daif in history, according to the more correct view.