Narrated Ibn 'Umar:
that the Messenger of Allah (ﷺ) said: "If you see those who abuse my Companions, then say: 'May Allah's curse be upon the worst of you.'" (FR)
English reference (FR): Vol. 1, Book 46, Hadith 3866 (FR)
Arabic reference (FR): Book 49, Hadith 4240 (FR)