Abu Huraira reported: The Messenger of Allah, peace and blessings be upon him, said, “Among the signs of a hypocrite are three, even if he fasts and prays and claims to be a Muslim: when he speaks he lies, when he gives a promise he breaks it, and when he is trusted he betrays.”
Source: Ṣaḥīḥ al-Bukhārī 33, Ṣaḥīḥ Muslim 59
Grade: Muttafaqun Alayhi (authenticity agreed upon) according to Al-Bukhari and Muslim
عَنْ أَبِي هُرَيْرَةَ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ مِنْ عَلَامَاتِ الْمُنَافِقِ ثَلَاثَةٌ وَإِنْ صَامَ وَصَلَّى وَزَعَمَ أَنَّهُ مُسْلِمٌ إِذَا حَدَّثَ كَذَبَ وَإِذَا وَعَدَ أَخْلَفَ وَإِذَا اؤْتُمِنَ خَانَ
33 صحيح البخاري كتاب الإيمان باب علامة المنافق
59 صحيح مسلم كتاب الإيمان باب بيان خصال المنافق