Sunan Ibn Majah, Volume 4, Book 24, Hadith 2861 (DarusSalam) ⓘ

It was narrated from Umm Husain that she heard the Messenger of Allah say: “Even if the one appointed over you is a mutilated Ethiopian slave whose nose and ears have been cut off, listen to him and obey, so long as he leads you according to the Book of Allah.”

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا وَكِيعُ بْنُ الْجَرَّاحِ، عَنْ شُعْبَةَ، عَنْ يَحْيَى بْنِ الْحُصَيْنِ، عَنْ جَدَّتِهِ أُمِّ الْحُصَيْنِ، قَالَتْ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ ‏ "‏ إِنْ أُمِّرَ عَلَيْكُمْ عَبْدٌ حَبَشِيٌّ مُجَدَّعٌ فَاسْمَعُوا لَهُ وَأَطِيعُوا مَا قَادَكُمْ بِكِتَابِ اللَّهِ ‏" ‏ ‏.‏