During the first few months after Muhammad's arrival in Medina, the Banu Qurayza were involved in a dispute with the Banu Nadir: The more powerful Nadir rigorously applied "lex talionis" against the Qurayza while not allowing it being enforced against themselves. Further, the blood money paid for killing a man of the Qurayza was only half of the blood-money required for killing a man of the Nadir, placing the Qurayza in a socially inferior position. The Qurayza called on Muhammad as arbitrator, who delivered the surah and judged that the Nadir and Qurayza should be treated alike in the application of lex talionis and raised the assessment of the Qurayza to the full amount of blood money.