Musannaf Ibn Abi Shaybah

It is narrated from Hazrat Ibn Abbas (may Allah be pleased with them both) that the Holy Prophet (peace and blessings be upon him) wrote to the Muhajireen and Ansar that blood money should be given in cases of their killing, and ransom for their captives will be taken in a good manner, and reconciliation will be established among the Muslims (in their affairs).