كتاب الإمارة
33
The Book on Government
(8)
Chapter: The obligation of obeying leaders in matters that do not involve sin, but it is forbidden to obey them in sinful matters
(8)
باب وُجُوبِ طَاعَةِ الأُمَرَاءِ فِي غَيْرِ مَعْصِيَةٍ وَتَحْرِيمِهَا فِي الْمَعْصِيَةِ ‏‏
Sahih Muslim 1838 c

In other versions of the above tradition, the wordings are" an Abyssinian slave." and" a maimed Abyssinian slave".

وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا وَكِيعُ بْنُ الْجَرَّاحِ، عَنْ شُعْبَةَ، بِهَذَا الإِسْنَادِ وَقَالَ عَبْدًا حَبَشِيًّا مُجَدَّعًا ‏.‏
Reference : Sahih Muslim 1838 c
In-book reference : Book 33, Hadith 58
USC-MSA web (English) reference : Book 20, Hadith 4530
  (deprecated numbering scheme)