The Prophet ﷺ said: Conciliation between Muslims is permissible. The narrator Ahmad added in his version: "except the conciliation which makes lawful unlawful and unlawful lawful." Sulayman ibn Dawud added: The Messenger of Allah ﷺ said: Muslims are on (i.e. stick to) their conditions.  

قَالَ رَسُولُ اللَّهِ ﷺ الصُّلْحُ جَائِزٌ بَيْنَ الْمُسْلِمِينَ زَادَ أَحْمَدُ إِلاَّ صُلْحًا أَحَلَّ حَرَامًا أَوْ حَرَّمَ حَلاَلاً وَزَادَ سُلَيْمَانُ بْنُ دَاوُدَ وَقَالَ رَسُولُ اللَّهِ ﷺ الْمُسْلِمُونَ عَلَى شُرُوطِهِمْ  

"Reconciliation is allowed among the Muslims, except for reconciliation that makes the lawful unlawful, or the unlawful lawful. And the Muslims will be held to their conditions, except the conditions that make the lawful unlawful, or the unlawful lawful."  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ الصُّلْحُ جَائِزٌ بَيْنَ الْمُسْلِمِينَ إِلاَّ صُلْحًا حَرَّمَ حَلاَلاً أَوْ أَحَلَّ حَرَامًا وَالْمُسْلِمُونَ عَلَى شُرُوطِهِمْ إِلاَّ شَرْطًا حَرَّمَ حَلاَلاً أَوْ أَحَلَّ حَرَامًا  

“I heard the Messenger of Allah ﷺ say: 'Reconciling between Muslims is permissible, except reconciliation that forbids something that is allowed, or allows something that is forbidden.'”  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ الصُّلْحُ جَائِزٌ بَيْنَ الْمُسْلِمِينَ إِلاَّ صُلْحًا حَرَّمَ حَلاَلاً أَوْ أَحَلَّ حَرَامًا  

“I heard the Messenger of Allah ﷺ say: 'Reconciling between Muslims is permissible, except reconciliation that forbids something that is allowed, or allows something that is forbidden.'” (Using translation from Ibn Mājah 2353)   

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ «الصُّلْحُ جَائِزٌ بَيْنَ الْمُسْلِمِينَ إِلَّا صُلْحًا حَرَّمَ حَلَالًا أَوِ أَحَلَّ حَرَامًا وَإِنَّ الْمُسْلِمِينَ عَلَى شُرُوطِهِمْ إِلَّا شَرْطًا حَرَّمَ حَلَالًا» واه  

“I heard the Messenger of Allah ﷺ say: 'Reconciling between Muslims is permissible, except reconciliation that forbids something that is allowed, or allows something that is forbidden.'” (Using translation from Ibn Mājah 2353)   

قَالَ رَسُولُ اللَّهِ ﷺ «الصُّلْحُ جَائِزٌ بَيْنَ الْمُسْلِمِينَ إِلَّا صُلْحًا أَحَلَّ حَرَامًا أَوْ حَرَّمَ حَلَالًا»  

[Machine] "On the authority of the Messenger of Allah ﷺ, he said: 'Muslims are bound by their conditions, except a condition that makes the permissible forbidden, and makes the forbidden permissible. Reconciliation is permissible among people, except a reconciliation that makes the forbidden permissible, or makes the permissible forbidden.'"  

عَنْ رَسُولِ اللهِ ﷺ قَالَ «الْمُسْلِمُونَ عَلَى شُرُوطِهِمْ إِلَّا شَرْطًا حَرَّمَ حَلَالًا وَأَحَلَّ حَرَامًا وَالصُّلْحُ جَائِزٌ بَيْنَ النَّاسِ إِلَّا صُلْحًا أَحَلَّ حَرَامًا أَوْ حَرَّمَ حَلَالًا»  

"المسلمون على شروطهم إلا شرطًا حَرَّمَ حَلالًا أوَ أَحَلَّ حَرَامًا، وَالصلحُ جَائِزٌ بين النَّاسِ إلا صلحًا أَحلَّ حَرَامًا أَوْ حَرَّمَ حَلالًا".