وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّهُ كَانَ يَقُولُ لاَ يَطَأُ الرَّجُلُ وَلِيدَةً إِلاَّ وَلِيدَةً إِنْ شَاءَ بَاعَهَا وَإِنْ شَاءَ وَهَبَهَا وَإِنْ شَاءَ أَمْسَكَهَا وَإِنْ شَاءَ صَنَعَ بِهَا مَا شَاءَ ‏.‏ قَالَ مَالِكٌ فِيمَنِ اشْتَرَى جَارِيَةً عَلَى شَرْطِ أَنْ لاَ يَبِيعَهَا أَوْ لاَ يَهَبَهَا أَوْ مَا أَشْبَهَ ذَلِكَ مِنَ الشُّرُوطِ فَإِنَّهُ لاَ يَنْبَغِي لِلْمُشْتَرِي أَنْ يَطَأَهَا وَذَلِكَ أَنَّهُ لاَ يَجُوزُ لَهُ أَنْ يَبِيعَهَا وَلاَ يَهَبَهَا فَإِذَا كَانَ لاَ يَمْلِكُ ذَلِكَ مِنْهَا فَلَمْ يَمْلِكْهَا مِلْكًا تَامًّا لأَنَّهُ قَدِ اسْتُثْنِيَ عَلَيْهِ فِيهَا مَا مَلَكَهُ بِيَدِ غَيْرِهِ فَإِذَا دَخَلَ هَذَا الشَّرْطُ لَمْ يَصْلُحْ وَكَانَ بَيْعًا مَكْرُوهًا ‏.‏

Yahya related to me from Malik from Nafi that Abdullah ibn Umarwould say, "A man should not have intercourse with a slave girl exceptone whom, if he wished, he could sell, if he wished, he could giveaway, if he wished, he could keep, if he wished, he could do with herwhat he wanted ." Malik said that a man who bought a slave-girl on condition that he did not sell her, give her away, or dosomething of that nature, was not to have intercourse with her. Thatwas because he was not permitted to sell her or to give her away, soif he did not own that from her, he did not have complete ownership ofher because an exception had been made concerning her by the hand ofsomeone else. If that sort of condition entered into it, it was amessy situation, and the sale was not recommended. Translation Not Available

Book reference: Muwatta Imam Malik Book 31 Hadith 1298
Web reference: Muwatta Imam Malik Book 31 Hadith 6