Al-Adab Al-Mufrad, Book 56, Hadith 1309 (In-Book) ⓘ
Abu Hurayra reported that the Messenger of Allah, may Allah bless him and grant him peace, said, "The worst person is someone who is two-faced. He is the person who comes to one group of people with one face and another group of people with another face."
حَدَّثَنَا إِسْمَاعِيلُ قَالَ: حَدَّثَنِي مَالِكٌ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللهِ صلى الله عليه وسلم قَالَ: مِنْ شَرِّ النَّاسِ ذُو الْوَجْهَيْنِ، الَّذِي يَأْتِي هَؤُلاَءِ بِوَجْهٍ، وَهَؤُلاَءِ بِوَجْهٍ.
also referenced under: Hadith 1309 (Reference) & Book 56, Hadith 1309 (English)