Hadithcore
Sunan Abi Dawud, 1728
sahih· Al-Albani

Nafi` said :

Ibn `Umr used to seat his slave girl called Safiyyah behind him(on the Camel) and thus she travelled to Makkah in his company.

حَدَّثَنَا نَصْرُ بْنُ عَلِيٍّ، حَدَّثَنَا أَبُو أَحْمَدَ، حَدَّثَنَا سُفْيَانُ، عَنْ عُبَيْدِ اللَّهِ، عَنْ نَافِعٍ، أَنَّ ابْنَ عُمَرَ، كَانَ يُرْدِفُ مَوْلاَةً لَهُ يُقَالُ لَهَا صَفِيَّةُ تُسَافِرُ مَعَهُ إِلَى مَكَّةَ ‏.‏

References2 variants
In-Book Reference
Book 11, Hadith 8
English Reference
Book 10, Hadith 1724