It is narrated from Sayyiduna Abdullah bin Amr (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) said: "There are three kinds of people at whom Allah Almighty will not look (with mercy) on the Day of Resurrection, nor will He purify them, and for them is a painful punishment: a man who comes to a people who are united and firm upon Islam, then shatters their unity, until they come to regard forbidden things as lawful and begin to shed blood; and the second, a tyrannical ruler." And he (peace and blessings be upon him) said: "Whoever obeys me has obeyed Allah, and whoever disobeys me has disobeyed Allah." The narrator says that Sufyan (may Allah have mercy on him) kept silent about the third person and did not mention him.
Hadith Referenceالمعجم الأوسط / باب الألف / 2401
Hadith Gradingمحدثین:فيه إبراهيم بن بشار الرمادي صدوق كثير الوهم، وبقية رجاله ثقات
Hadith Takhrij«قال الهيثمي: وفيه إبراهيم بن بشار الرمادي وهو صدوق كثير الوهم وبقية رجاله ثقات «مجمع الزوائد ومنبع الفوائد، ج 5، ص 237»»