(19) باب فِي الْمَمْلُوكَةِ تَعْتِقُ وَهِيَ تَحْتَ حُرٍّ أَوْ عَبْدٍ
While relating the tradition about Barirah A'ishah said "her husband was a slave, so the Prophet(ﷺ) gave her choice. She chose herself. Had he been a free man, he would not given her choice."
Reference: Sunan Abi Dawud 2233
In-book reference: Book 13, Hadith 59
English translation: Book 12, Hadith 2225