Hadithcore
Sunan Abi Dawud, 5160
sahih· Al-Albani

The tradition mentioned above has also been transmitted by al-A’mash in a similar way to same way to the same effect through a different chain of narrators.

حَدَّثَنَا أَبُو كَامِلٍ، حَدَّثَنَا عَبْدُ الْوَاحِدِ، عَنِ الأَعْمَشِ، بِإِسْنَادِهِ وَمَعْنَاهُ نَحْوَهُ قَالَ كُنْتُ أَضْرِبُ غُلاَمًا لِي أَسْوَدَ بِالسَّوْطِ وَلَمْ يَذْكُرْ أَمْرَ الْعِتْقِ ‏.‏

References2 variants
In-Book Reference
Book 43, Hadith 388
English Reference
Book 42, Hadith 5141