Sayyiduna Nufayr bin Malik (may Allah be pleased with him) narrates that the Prophet (peace and blessings be upon him) said: "The descendants of Sayyiduna Abbas (may Allah be pleased with him) will not come to an end until the tribes of the Arabs rise up against them. The situation at that time will be at its harshest for them, when they will have neither any helper in the heavens nor anyone on earth to make an excuse for them. It is as though I can see them even now, riding their mules in the midst of Kufah, and at that time a secluded young woman behind her curtain will say: 'Kill them! May Allah Almighty kill them. Do not show them mercy; may Allah Almighty show them no mercy, for they showed us no mercy for a long time.'"
Al-Tabarani recorded it; its chain contains narrators whom I do not know. Some hadiths of this kind will come later in the chapter on oppressive and tyrannical rulers, if Allah wills.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الخلافة / 8959