Sahih al-Bukhari, Hadith 2561 ⓘ
Narrated `Urwa: That `Aisha told him that Buraira came to seek her help in her writing of emancipation (for a certain sum) and that time she had not paid anything of it. `Aisha said to her, "Go back to your masters, and if they agree that I will pay the amount of your writing of emancipation and get your Wala', I will do so." Buraira informed her masters of that but they refused and said, "If she (i.e. `Aisha) is seeking Allah's reward, then she can do so, but your Wala' will be for us." `Aisha mentioned that to Allah's Apostle who said to her, "Buy and manumit her, as the Wala' is for the liberator." Allah's Messenger then got up and said, "What about the people who stipulate conditions which are not present in Allah's Laws? Whoever imposes conditions which are not present in Allah's Laws, then those conditions will be invalid, even if he imposed these conditions a hundred times. Allah's conditions (Laws) are the truth and are more solid."
حَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا اللَّيْثُ، عَنِ ابْنِ شِهَابٍ، عَنْ عُرْوَةَ، أَنَّ عَائِشَةَ ـ رضى الله عنها ـ أَخْبَرَتْهُ أَنَّ بَرِيرَةَ جَاءَتْ تَسْتَعِينُهَا فِي كِتَابَتِهَا، وَلَمْ تَكُنْ قَضَتْ مِنْ كِتَابَتِهَا شَيْئًا، قَالَتْ لَهَا عَائِشَةُ ارْجِعِي إِلَى أَهْلِكِ، فَإِنْ أَحَبُّوا أَنْ أَقْضِيَ عَنْكِ كِتَابَتَكِ، وَيَكُونَ وَلاَؤُكِ لِي فَعَلْتُ. فَذَكَرَتْ ذَلِكَ بَرِيرَةُ لأَهْلِهَا فَأَبَوْا وَقَالُوا إِنْ شَاءَتْ أَنْ تَحْتَسِبَ عَلَيْكِ فَلْتَفْعَلْ، وَيَكُونَ وَلاَؤُكِ لَنَا، فَذَكَرَتْ ذَلِكَ لِرَسُولِ اللَّهِ صلى الله عليه وسلم فَقَالَ لَهَا رَسُولُ اللَّهِ صلى الله عليه وسلم " ابْتَاعِي فَأَعْتِقِي، فَإِنَّمَا الْوَلاَءُ لِمَنْ أَعْتَقَ ". قَالَ ثُمَّ قَامَ رَسُولُ اللَّهِ صلى الله عليه وسلم فَقَالَ " مَا بَالُ أُنَاسٍ يَشْتَرِطُونَ شُرُوطًا لَيْسَتْ فِي كِتَابِ اللَّهِ مَنِ اشْتَرَطَ شَرْطًا لَيْسَ فِي كِتَابِ اللَّهِ فَلَيْسَ لَهُ، وَإِنْ شَرَطَ مِائَةَ مَرَّةٍ، شَرْطُ اللَّهِ أَحَقُّ وَأَوْثَقُ ".
also referenced under: Book 50, Hadith 2 (In-Book) & Volume 3, Book 46, Hadith 735 (USC-MSA)