Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "I do not fear for my Ummah either a believer or a polytheist. As for the believer, his faith will protect him; as for the polytheist, his disbelief will ruin him. Rather, I fear for you a hypocrite who is skilled in speech; he will say what seems known (ma'ruf) to you and do what seems objectionable (munkar) to you."
Tabarani recorded it in al-Mu'jam al-Awsat and al-Mu'jam al-Saghir; the chain of this report contains a narrator named al-Harith al-A'war, who is extremely da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب العلم / 884
Hadith Gradingمحدثین:إسنادہ ضعیف جداً
Hadith Takhrij«اخرجه الامام الطبراني فى معجم الاوسط 7065 اخرجه الامام الطبراني فى معجمه الصغير 93/2 ، أخرجه المعجم الأوسط للطبراني برقم: 7061، وأخرجه المعجم الصغير للطبراني برقم: 984، وأخرجه إتحاف الخيرة المهرة بزوائد المسانيد العشرة برقم: 385، 7083»