Abdullah ibn Amr reported: The Messenger of Allah, peace and blessings be upon him, said:
There are four signs that make someone a pure hypocrite and whoever has them has a characteristic of hypocrisy until he abandons it: when he speaks he lies, when he makes a covenant he is treacherous, when he makes a promise he breaks it, and when he argues he is wicked.
Ṣaḥīḥ al-Bukhārī 34, Grade: Muttafaqun Alayhi
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