Hadithcore
Sunan Abi Dawud, 4518
sahih· Al-Albani

It was narrated from Hisham, from Qatadah, from Al-Hasan, who said:

"A free man should not be subjected to retaliation in return for a slave."

حَدَّثَنَا مُسْلِمُ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا هِشَامٌ، عَنْ قَتَادَةَ، عَنِ الْحَسَنِ، قَالَ لاَ يُقَادُ الْحُرُّ بِالْعَبْدِ ‏.‏

References2 variants
In-Book Reference
Book 41, Hadith 25
English Reference
Book 40, Hadith 4503