Musannaf Ibn Abi Shayba 37:244

Sufyan ibn Uyaynah narrated to us, from al-Zuhri, from Sa'id, from Abu Hurayrah, who attributed it to the Prophet (may Allah bless him and grant him peace), who said: "The Hour will not be established until you fight a people whose sandals are made of hair. And the Hour will not be established until you fight a people with small eyes."