Sahih Bukhari Volume 1, Book 2, Hadith 34

حَدَّثَنَا قَبِيصَةُ بْنُ عُقْبَةَ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنِ الأَعْمَشِ، عَنْ عَبْدِ اللَّهِ بْنِ مُرَّةَ، عَنْ مَسْرُوقٍ، عَنْ عَبْدِ اللَّهِ بْنِ عَمْرٍو، أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ ‏"‏ أَرْبَعٌ مَنْ كُنَّ فِيهِ كَانَ مُنَافِقًا خَالِصًا، وَمَنْ كَانَتْ فِيهِ خَصْلَةٌ مِنْهُنَّ كَانَتْ فِيهِ خَصْلَةٌ مِنَ النِّفَاقِ حَتَّى يَدَعَهَا إِذَا اؤْتُمِنَ خَانَ وَإِذَا حَدَّثَ كَذَبَ وَإِذَا عَاهَدَ غَدَرَ، وَإِذَا خَاصَمَ فَجَرَ ‏"‏‏.‏ تَابَعَهُ شُعْبَةُ عَنِ الأَعْمَشِ

Narrated By 'Abdullah bin 'Amr : The Prophet said, "Whoever has the following four (characteristics) will be a pure hypocrite and whoever has one of the following four characteristics will have one characteristic of hypocrisy unless and until he gives it up. 1. Whenever he is entrusted, he betrays. 2. Whenever he speaks, he tells a lie. 3. Whenever he makes a covenant, he proves treacherous. 4. Whenever he quarrels, he behaves in a very imprudent, evil and insulting manner."