The Prophet (SAW) said: Hear and obey, even if an Ethiopian with a head like a raisin [zabiba] were made chief over you.
- Sahih Al-Bukhari, The book of rulings

His words "with a head like a raisin" : … He likened the head of Ethiopians to a raisin due to it being scrunched up and the fact that their hair is black - symbolizing how repugnant it is and how hideous it looks and the lack of any esteem for it.