It was narrated from Umm Husain that she heard the Messenger of Allah ﷺ 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 ﷺ يَقُولُ " إِنْ أُمِّرَ عَلَيْكُمْ عَبْدٌ حَبَشِيٌّ مُجَدَّعٌ فَاسْمَعُوا لَهُ وَأَطِيعُوا مَا قَادَكُمْ بِكِتَابِ اللَّهِ " .