Musannaf Ibn Abi Shayba 37:245

Ibn ‘Uyaynah narrated to us, from Abu al-Zinad, from al-A’raj, from Abu Hurayrah, attributing it to the Prophet (may Allah bless him and grant him peace): "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 and flat noses, as if their faces are hammered shields."