Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) reports this saying of the Prophet (peace and blessings be upon him): "Whoever raises a weapon against us is not one of us."
Al-Tabarani recorded it in al-Mu'jam al-Awsat; its chain contains Ayyub bin Utbah, who is da'if (weak), and according to one report Yahya bin Ma'in declared him thiqah (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الفتن - أعاذنا الله منها / 12273
Hadith Gradingمحدثین:إسنادہ ضعیف
Hadith Takhrij«أخرجه المعجم الأوسط للطبراني برقم: 5835»