Messenger of Allah ﷺ came to me and I told him about the slave-girl (Barirah) Messenger of Allah ﷺ said, "Buy and manumit her, for the Wala is for the one who manumits." In the evening the Prophet ﷺ got up and glorified Allah as He deserved and then said, "Why do some people impose conditions which are not present in Allah's Book (Laws)? Whoever imposes such a condition as is not in Allah's Laws, then that condition is invalid even if he imposes one hundred conditions, for Allah's conditions are more binding and reliable."  

عَائِشَةُ ؓ دَخَلَ عَلَىَّ رَسُولُ اللَّهِ ﷺ فَذَكَرْتُ لَهُ فَقَالَ رَسُولُ اللَّهِ ﷺ اشْتَرِي وَأَعْتِقِي فَإِنَّ الْوَلاَءَ لِمَنْ أَعْتَقَ ثُمَّ قَامَ النَّبِيُّ ﷺ مِنَ الْعَشِيِّ فَأَثْنَى عَلَى اللَّهِ بِمَا هُوَ أَهْلُهُ ثُمَّ قَالَ مَا بَالُ أُنَاسٍ يَشْتَرِطُونَ شُرُوطًا لَيْسَ فِي كِتَابِ اللَّهِ مَنِ اشْتَرَطَ شَرْطًا لَيْسَ فِي كِتَابِ اللَّهِ فَهْوَ بَاطِلٌ وَإِنِ اشْتَرَطَ مِائَةَ شَرْطٍ شَرْطُ اللَّهِ أَحَقُّ وَأَوْثَقُ  

Aisha said that Barirah came to seek her help in the writing of her emancipation. ʿAisha said to her, "If you wish, I will pay your masters (your price) and the wala' will be for me." When Messenger of Allah ﷺ came, she told him about it. The Prophet ﷺ said to her, "Buy her (i.e. Barirah) and manumit (free) her, for the Wala is for the one who manumits." Then Messenger of Allah ﷺ ascended the pulpit and said, "What about those people who stipulate conditions which are not in Allah's Laws? Whoever stipulates such conditions as are not in Allah's Laws, then those conditions are invalid even if he stipulated a hundred such conditions."  

إِنْ شِئْتِ أَعْطَيْتُ أَهْلَكِ وَيَكُونُ الْوَلاَءُ لِي فَلَمَّا جَاءَ رَسُولُ اللَّهِ ﷺ ذَكَّرْتُهُ ذَلِكَ قَالَ النَّبِيُّ ﷺ ابْتَاعِيهَا فَأَعْتِقِيهَا فَإِنَّمَا الْوَلاَءُ لِمَنْ أَعْتَقَ ثُمَّ قَامَ رَسُولُ اللَّهِ ﷺ عَلَى الْمِنْبَرِ فَقَالَ مَا بَالُ أَقْوَامٍ يَشْتَرِطُونَ شُرُوطًا لَيْسَتْ فِي كِتَابِ اللَّهِ مَنِ اشْتَرَطَ شَرْطًا لَيْسَ فِي كِتَابِ اللَّهِ فَلَيْسَ لَهُ وَإِنِ اشْتَرَطَ مِائَةَ شَرْطٍ  

"أمَّا بعدُ فما بَالُ أَقْوَامٍ يَشْتَرِطُونَ شُرُوطًا ليست في كتاب اللهِ ما كان من شَرْطٍ ليس في كتاب الله فهو بَاطِلٌ، وإن كان مائة شرطٍ، قضاء الله أَحَقُّ، وشَرْطُ اللهِ أَوثَقُ وَإنَّما الوَلاءُ لِمَنْ أَعْتَقَ".