The Prophet ﷺ said, "Some people from among my companions will come to me at the Pool, and just as I recognize them, they will be snatched away from me. I will say, 'My companions!' But it will be said, 'You do not know what they introduced after you.'"
عن النبي ﷺ قال: ليردن علي ناس من أصحابي الحوض، حتى إذا عرفتهم اختلجوا دوني فأقول: أصحابي؟ فيقول: لا تدري ما أحدثوا بعدك.
Bukhari narrated it in Riqaq (6582), and Muslim in Fadail (2304), both from the hadith of Wahib, who said, Abdul-Aziz bin Suhayb told us, narrating, he said, Anas bin Malik told us, and he related the hadith. Their wording is the same, except that in Muslim's wording it reads, "My companions, my companions!" And it will be said to me, "You do not know what they introduced after you."