Muwatta Imam Malik Book of Business Transactions, Hadith 8
Yahya related to me from Malik from Ibn Shihab from Abu Salama ibn Abd ar-Rahman ibn Awf that Abd ar-Rahman ibn Awf bought a slave- girl and found that she had a husband, so he returned her.
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنْ أَبِي سَلَمَةَ بْنِ عَبْدِ الرَّحْمَنِ بْنِ عَوْفٍ، أَنَّ عَبْدَ الرَّحْمَنِ بْنَ عَوْفٍ، ابْتَاعَ وَلِيدَةً فَوَجَدَهَا ذَاتَ زَوْجٍ فَرَدَّهَا .