Mishkat al-Masabih 11 Business Transactions كتاب البيوع 159

وَعَن عَمْرو بن عَوْف الْمُزَنِيِّ عَنِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: «الصُّلْحُ جَائِزٌ بَيْنَ الْمُسْلِمِينَ إِلَّا صُلْحًا حَرَّمَ حَلَالًا أَوْ أَحَلَّ حَرَامًا وَالْمُسْلِمُونَ عَلَى شُرُوطِهِمْ إِلَّا شَرْطًا حَرَّمَ حَلَالًا أَوْ أَحَلَّ حَرَامًا» . رَوَاهُ التِّرْمِذِيُّ وَابْنُ مَاجَهْ وَأَبُو دَاوُدَ وَانْتَهَتْ رِوَايَته عِنْد قَوْله «شروطهم»

‘Amr b. ‘Auf al-Muzani reported the Prophet as saying, “Reconciliation is allowable between Muslims except such as makes unlawful something which is lawful, or makes lawful something which is unlawful ; and Muslims must keep to the conditions they have made, except for a condition which makes unlawful something which is lawful, or makes lawful something which is unlawful.” Tirmidhi, Ibn Majah and Abu Dawud transmitted it, but Abu Dawud’s transmission ended at “the conditions they have made.”