Sahih al-Bukhari 3493, 3494Book 61, Hadith 5
حَدَّثَنِي إِسْحَاقُ بْنُ إِبْرَاهِيمَ، أَخْبَرَنَا جَرِيرٌ، عَنْ عُمَارَةَ، عَنْ أَبِي زُرْعَةَ، عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ " تَجِدُونَ النَّاسَ مَعَادِنَ، خِيَارُهُمْ فِي الْجَاهِلِيَّةِ خِيَارُهُمْ فِي الإِسْلاَمِ إِذَا فَقِهُوا، وَتَجِدُونَ خَيْرَ النَّاسِ فِي هَذَا الشَّأْنِ أَشَدَّهُمْ لَهُ كَرَاهِيَةً ". " وَتَجِدُونَ شَرَّ النَّاسِ ذَا الْوَجْهَيْنِ، الَّذِي يَأْتِي هَؤُلاَءِ بِوَجْهٍ، وَيَأْتِي هَؤُلاَءِ بِوَجْهٍ ".
Allah's Messenger (ﷺ) said, "You see that the people are of different natures. Those who were the best in the pre-lslamic period, are also the best in Islam if they comprehend religious knowledge. You see that the best amongst the people in this respect (i.e. ambition of ruling) are those who hate it most. And you see that the worst among people is the double faced (person) who appears to these with one face and to the others with another face (i.e a hypocrite).