Sahih al-Bukhari 92:4
Abu Sa`id Al-Khudri added that the Prophet (ﷺ) further said:
"I will say those people are from me. It will be said, 'You do not know what changes and new things they did after you.' Then I will say, 'Far removed (from mercy), far removed (from mercy), those who changed (the religion) after me!"
Reference
Sahih al-Bukhari 92:4
In-book reference
Book 92, Hadith 4
Arabic Text
قَالَ أَبُو حَازِمٍ فَسَمِعَنِي النُّعْمَانُ بْنُ أَبِي عَيَّاشٍ، وَأَنَا أُحَدِّثُهُمْ، هَذَا فَقَالَ هَكَذَا سَمِعْتَ سَهْلاً، فَقُلْتُ نَعَمْ. قَالَ وَأَنَا أَشْهَدُ، عَلَى أَبِي سَعِيدٍ الْخُدْرِيِّ لَسَمِعْتُهُ يَزِيدُ فِيهِ قَالَ " إِنَّهُمْ مِنِّي. فَيُقَالُ إِنَّكَ لاَ تَدْرِي مَا بَدَّلُوا بَعْدَكَ فَأَقُولُ سُحْقًا سُحْقًا لِمَنْ بَدَّلَ بَعْدِي ".