Abu al-Ash-hab Ja'far bin Hayyan al-Utaridi (may Allah have mercy on him) narrates from al-Hasan (al-Basri) (may Allah have mercy on him), who relates: Ubaydullah bin Ziyad visited Sayyiduna Ma'qil bin Yasar (may Allah be pleased with him) during the illness in which he died. Ma'qil (may Allah be pleased with him) said: I will tell you a hadith that I heard from the Messenger of Allah (peace and blessings be upon him); had I known that I had life remaining, I would not have told it to you. I heard him (peace and blessings be upon him) say: "Any servant whom Allah makes the guardian of a flock (of people) and he dies while being treacherous towards his flock, Allah Almighty forbids Paradise to him."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17608