The Messenger of Allah ﷺ wrote a document between the Muhajirun and the Ansar stipulating that they would jointly bear the blood-money obligations of their members, ransom their captives in accordance with what is right, and maintain reconciliation among the Muslims.
حدثنا نصر بن باب عن حجاج
أن رسول الله ﷺ كتب كتابا بين المهاجرين والأنصار على أن يعقلوا معاقلهم ويفدوا عانيهم بالمعروف والإصلاح بين المسلمين