It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) regarding the interpretation of the Qur’anic verse: «﴿فَإِنْجَاءُوكَفَاحْكُمْبَيْنَهُمْأَوْأَعْرِضْعَنْهُمْ . . . . .﴾ [المائدة : 42]» “If they come to you, you have the option either to judge between them or to turn them away, . . . . .” that if the people of Banu Nadir killed a man from Banu Qurayza, they would pay them half the blood money, and if the people of Banu Qurayza killed a man from Banu Nadir, they would be forced to pay the full blood money. The Prophet (peace and blessings be upon him) established equal blood money between the two tribes.
Hadith Referenceمسند احمد / ومن مسند بني هاشم / 3434