It is narrated from Sayyiduna Ali (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Ali! If at any time after me the reins of government come into your hands, then expel the people of Najran from the Arabian Peninsula."
Hadith Referenceمسند احمد / مسند الخلفاء الراشدين / 661
Hadith Gradingحکم دارالسلام:إسناده ضعيف جداً لضعف قيس- وهو أبن الربيع الأسدي الكوفي - و أشعث بن سوار