From Sahih Bukhari (Hadith 6582):
Narrated Anas:The Prophet (ﷺ) said, "Some of my companions will come to me at my Lake Fount, and after I recognize them, they will then be taken away from me, whereupon I will say, 'My companions!' Then it will be said, 'You do not know what they innovated (new things) in the religion after you
Reference: Bukhari 6582