From Sahih Bukhari (Hadith 6585):
Abu Huraira narrated that the Prophet (ﷺ) said:"On the Day of Resurrection a group of companions will come to me, but will be driven away from the Lake-Fount, and I will say, 'O Lord (those are) my companions!' It will be said, 'You have no knowledge as to what they innovated after you left; they turned apostate as renegades (reverted from Islam)
Reference: Bukhari 6585