وَحَدَّثَنِي مَالِكٌ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏"‏ مِنْ شَرِّ النَّاسِ ذُو الْوَجْهَيْنِ الَّذِي يَأْتِي هَؤُلاَءِ بِوَجْهٍ وَهَؤُلاَءِ بِوَجْهٍ ‏"‏ ‏.‏

Malik related to me from Abu'z-Zinad from al-Araj from AbuHurayra that the Messenger of Allah, may Allah bless him and grant himpeace, said, "One of the most evil of people is the two-faced personwho shows one face to these people and another face to those people." Translation Not Available

Book reference: Muwatta Imam Malik Book 56 Hadith 1834
Web reference: Muwatta Imam Malik Book 56 Hadith 21