Muwatta Malik, Book 31, Hadith 1298 (In-Book) ⓘ

Yahya related to me from Malik from Nafi that Abdullah ibn Umar would say, "A man should not have intercourse with a slave girl except one whom, if he wished, he could sell, if he wished, he could give away, if he wished, he could keep, if he wished, he could do with her what he wanted." Malik said that a man who bought a slave- girl on condition that he did not sell her, give her away, or do something of that nature, was not to have intercourse with her. That was because he was not permitted to sell her or to give her away, so if he did not own that from her, he did not have complete ownership of her because an exception had been made concerning her by the hand of someone else. If that sort of condition entered into it, it was a messy situation, and the sale was not recommended.

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 ‏.‏