أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ الأَعْلَى، قَالَ حَدَّثَنَا خَالِدٌ، قَالَ حَدَّثَنَا شُعْبَةُ، عَنْ يَحْيَى بْنِ حُصَيْنٍ، قَالَ سَمِعْتُ جَدَّتِي، تَقُولُ سَمِعْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقُولُ فِي حَجَّةِ الْوَدَاعِ ‏
"‏ وَلَوِ اسْتُعْمِلَ عَلَيْكُمْ عَبْدٌ حَبَشِيٌّ يَقُودُكُمْ بِكِتَابِ اللَّهِ فَاسْمَعُوا لَهُ وَأَطِيعُوا ‏"‏ ‏.‏

It was narrated that Yahya bin Husain said: "I heard my grandmother say: 'I heard the Messenger of Allah say, during the Farewell Pilgrimage: If an Ethiopian slave is appointed over you who rules according to the Book of Allah, then listen to him and obey."'