Narrated Abdullah ibn Abbas: When this verse was revealed: "If they do come to thee, either judge between them, or decline to interfere. . . . If thou judge, judge in equity between them. " Banu an-Nadir used to pay half blood-money if they killed any-one from Banu Qurayzah. When Banu Qurayzah killed anyone from Banu an-Nadir, they would pay full blood-money. So the Messenger of Allah ﷺ made it equal between them.