Narrated Abdullah Ibn Abbas: Qurayzah and Nadir (were two Jewish tribes). An-Nadir were nobler than Qurayzah. When a man of Qurayzah killed a man of an-Nadir, he would be killed. But if a man of an-Nadir killed a man of Qurayzah, a hundred wasq of dates would be paid as blood-money. When Prophethood was bestowed upon the Prophet ﷺ, a man of an-Nadir killed a man of Qurayzah. They said: Give him to us, we shall kill him. They replied: We have the Prophet ﷺ between you and us. So they came to him. Thereupon the following verse was revealed: "If thou judge, judge in equity between them. " "In equity" means life for a life. The following verse was then revealed: "Do they seek of a judgment of (the days) ignorance?" Abu Dawud said: Quraizah and al-Nadir were the descendants of Harun the Prophet ﷺ
Hadith Referenceسنن ابي داود / كتاب الديات / 4494
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:ضعيف, إسناده ضعيف, نسائي (4736), داود عن عكرمة منكر, انوار الصحيفه، صفحه نمبر 158
Benefits and Issues: The system of retribution (qisas) was also present among the Children of Israel, and all human lives are equal—no nation or tribe has any superiority over another. Islam abolished the concept of superiority based on tribe and clan, and made faith (iman) and piety (taqwa) the standard of excellence. Also, according to our esteemed researcher, this narration has a weak chain of transmission; however, other scholars have declared it authentic.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 4494