Musnad Ahmad 1034:109

Ibn Numayr narrated to us, al-A‘mash narrated to us, from ‘Abd al-Rahman ibn Tharwan, from ‘Amr ibn Hanzalah, who said: Hudhayfah said: "By Allah, Mudar will not leave a single believing servant of Allah except that they will persecute him or kill him, or Allah, the angels, and the believers will strike them, until they cannot even defend the tail of a hill." A man said to him: "Do you say this, O Abu ‘Abd Allah, while you are a man from Mudar?" He said: "I do not say except what the Messenger of Allah, may Allah bless him and grant him peace, said."