Sahih Muslim , Book 32, Hadith 6300 (USC-MSA) ⓘ
Abu Huraira reported Allah's Messenger as saying: The worst amongst the people is the double-faced one; he comes to some people with one face and to others with the other face.
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، قَالَ قَرَأْتُ عَلَى مَالِكٍ عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " إِنَّ مِنْ شَرِّ النَّاسِ ذَا الْوَجْهَيْنِ الَّذِي يَأْتِي هَؤُلاَءِ بِوَجْهٍ وَهَؤُلاَءِ بِوَجْهٍ " .
also referenced under: Book 45, Hadith 127 (In-Book) & Hadith 2526 (Reference)