"آيَةُ الْمُنَافِقِ ثَلَاثٌ إِذَا حَدَّثَ كَذَبَ وَإِذَا وَعَدَ أَخْلَفَ وَإِذَا اؤْتُمِنَ خَانَ
"There are three signs of a hypocrite: whenever he speaks, he lies; whenever he makes a promise, he breaks it; and whenever he is trusted, he betrays his trust." (Bukhari, Belief, 24)
