Sunan Abi Dawud, Hadith 4518 ⓘ
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 .
also referenced under: Hadith 4503 (Hasan)