Musnad Ahmad 818:2

Yazid ibn Harun narrated to us, al-Jurayri informed us, from Abu al-Ala’ ibn al-Shikhkhir, from Abd al-Rahman ibn Sahar al-Abdi, from his father, who said: I heard the Messenger of Allah, peace and blessings of Allah be upon him, saying: "The Hour will not be established until tribes are swallowed up by the earth, until it is said: 'Who remains of the children of so-and-so?'" I knew that he meant the Arabs, because the non-Arabs are only attributed to their villages.