Mubarak bin Fadalah (may Allah have mercy on him) narrates from al-Hasan (al-Basri) (may Allah have mercy on him) that Ubaydullah bin Ziyad came to visit Sayyiduna Ma'qil bin Yasar (may Allah be pleased with him) during the illness in which he died. He asked: How do you find yourself? Ma'qil (may Allah be pleased with him) said: In this condition of mine I have no hope (of recovering), and I will tell you a hadith that I heard from the Messenger of Allah (peace and blessings be upon him). He said: What is it? He said: I heard the Messenger of Allah (peace and blessings be upon him) say: "There is no one who is made the guardian of a flock (of people) and who dies, on the day he dies, while being treacherous towards them, except that he will not find the fragrance of Paradise - or he said: he will be among the people of Hell." He said: Why did you not tell me this hadith before today? He said: "Were it not for this condition of mine, I would not have told you this hadith."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17610