جَدَّتِي، تُحَدِّثُ أَنَّهَا سَمِعَتِ النَّبِيَّ صلى الله عليه وسلم يَخْطُبُ فِي حَجَّةِ الْوَدَاعِ وَهُوَ يَقُولُ " وَلَوِ اسْتُعْمِلَ عَلَيْكُمْ عَبْدٌ يَقُودُكُمْ بِكِتَابِ اللَّهِ فَاسْمَعُوا لَهُ وَأَطِيعُوا ".
It has been narrated on the authority of Yahya b. Husain who learnt the tradition from his grandmother. She said that she heard the Prophet (ﷺ) delivering his sermon on the occasion of the Last Pilgrimage. He was saying:If a slave is appointed over you and he conducts your affairs according to the Book of Allah, you should listen to him and obeey (his orders)
وَحَدَّثَنَا عَبْدُ الرَّحْمَنِ بْنُ بِشْرٍ، حَدَّثَنَا بَهْزٌ، حَدَّثَنَا شُعْبَةُ، بِهَذَا الإِسْنَادِ وَلَمْ يَذْكُرْ حَبَشِيًّا مُجَدَّعًا وَزَادَ أَنَّهَا سَمِعَتْ رَسُولَ اللَّهِ صلى الله عليه وسلم بِمِنًى أَوْ بِعَرَفَاتٍ
Another version of the tradition does not qualify the slave with the epithets" maimed, an Abyssinian" but makes the addition:" I have heard the Prophet (ﷺ) (say this) at Mina or 'Arafat
وَحَدَّثَنِي سَلَمَةُ بْنُ شَبِيبٍ، حَدَّثَنَا الْحَسَنُ بْنُ أَعْيَنَ، حَدَّثَنَا مَعْقِلٌ، عَنْ زَيْدِ بْنِ أَبِي، أُنَيْسَةَ عَنْ يَحْيَى بْنِ حُصَيْنٍ، عَنْ جَدَّتِهِ أُمِّ الْحُصَيْنِ، قَالَ سَمِعْتُهَا تَقُولُ، حَجَجْتُ مَعَ رَسُولِ اللَّهِ صلى الله عليه وسلم حَجَّةَ الْوَدَاعِ - قَالَتْ - فَقَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم قَوْلاً كَثِيرًا ثُمَّ سَمِعْتُهُ يَقُولُ " إِنْ أُمِّرَ عَلَيْكُمْ عَبْدٌ مُجَدَّعٌ - حَسِبْتُهَا قَالَتْ - أَسْوَدُ يَقُودُكُمْ بِكِتَابِ اللَّهِ فَاسْمَعُوا لَهُ وَأَطِيعُوا ".
It has been narrated on the authority of Yahya b. Husain who learnt the tradition from his grandmother. Umm Husain. He said':I heard her say: I performed Hajjat-ul-Wada' in the company of the Messenger of Allah (ﷺ). He said a lot of things (on this occasion). Then I heard him say: If a maimed slave is appointed a commander over you the narrator says: I think she said:" a black stave" who leads you according to the Book of Allah, then listen to him and obey him