Abdullah bin Abbas reported,

Allah revealed, "And whoever does not judge by what Allah has revealed, those are the disbelievers", "And whoever does not judge by what Allah has revealed, those are the wrongdoers", "And whoever does not judge by what Allah has revealed, those are the defiantly disobedient" [Maidah 5:44–47].Ibn Abbas said, "Allah revealed these verses concerning two groups of Jews. One of them had subjugated the other during the days of ignorance, until they agreed and settled on the following arrangement. For every person from the weaker tribe killed by the stronger tribe, the blood-money would be fifty wasqs, and for every person from the stronger tribe killed by the weaker tribe, the blood-money would be one hundred wasqs.They continued on this basis until the Prophet ﷺ arrived in Medina, at which point both tribes became subdued by the arrival of the Messenger of Allah ﷺ. At that time, however, the Messenger of Allah ﷺ had not yet gained dominance over them and had not imposed his authority upon them, as he was in a state of truce.Then the weaker tribe killed someone from the stronger tribe, and the stronger tribe sent word to the weaker, 'Send us one hundred wasqs.'The weaker tribe replied, 'Has there ever been such a thing among two tribes whose religion is one, whose lineage is one, and whose town is one, that the blood-money of one is half the blood-money of the other? We only gave you this out of oppression from you against us and out of fear of you. But now that Muhammad has come, we will not give you that.'War nearly broke out between them, but they then agreed to make the Messenger of Allah ﷺ the arbiter between them.Then the stronger tribe reconsidered and said, 'By Allah, Muhammad is not going to give you double from them what he gives them from you. They have spoken the truth. They only gave us this out of oppression from us and our domination over them. So send to Muhammad someone who can find out his opinion for you. If he gives you what you want, then accept his arbitration, but if he does not give you what you want, then be cautious and do not submit to his judgment.'So they sent some hypocrites to the Messenger of Allah ﷺ to find out for them the opinion of the Messenger of Allah ﷺ. When they came to the Messenger of Allah ﷺ, Allah informed His Messenger of their entire affair and what they intended.Then Allah revealed, "Messenger, let not those who hasten into disbelief grieve you, from among those who say, 'We believe'" up to His words, "And whoever does not judge by what Allah has revealed, those are the defiantly disobedient" [Maidah 5:41–47]."Then he said about these two tribes, "By Allah, it was concerning them that the verses were revealed, and it was them that Allah meant."

عن ابن عباس، قال

إن الله عز وجل أنزل: {ومن لم يحكم بما أنزل الله فأولئك هم الكافرون} {ومن لم يحكم بما أنزل الله فأولئك هم الظالمون} {ومن لم يحكم بما أنزل الله فأولئك هم الفاسقون} قال: قال ابن عباس: أنزلها الله في الطائفتين من اليهود، وكانت إحداهما قد قهرت الأخرى في الجاهلية، حتى ارتضوا واصطلحوا على أن كل قتيل قتلته العزيزة من الذليلة، فديته خمسون وسقا، وكل قتيل قتلته الذليلة من العزيزة، فديته مائة وسق. فكانوا على ذلك حتى قدم النبي ﷺ المدينة، وذلت الطائفتان كلتاهما لمقدم رسول الله ﷺ، ورسول الله ﷺ يومئذ لم يظهر، ولم يوطئهما عليه، وهو في الصلح، فقتلت الذليلة من العزيزة قتيلا، فأرسلت العزيزة إلى الذليلة: أن ابعثوا إلينا بمائة وسق، فقالت الذليلة: وهل كان هذا في حيين قط دينهما واحد، ونسبهما واحد، وبلدهما واحد، دية بعضهم نصف دية بعض؟ إنما أعطيناكم هذا ضيما منكم لنا، وفرقا منكم، فأما إذ قدم محمد فلا نعطيكم ذلك، فكادت الحرب تهيج بينهما، ثم ارتضوا على أن يجعلوا رسول الله ﷺ بينهم، ثم ذكرت العزيزة، فقالت: والله ما محمد بمعطيكم منهم ضعف ما يعطيهم منكم، ولقد صدقوا، ما أعطونا هذا إلا ضيما منا، وقهرا لهم، فدسوا إلى محمد من يخبر لكم رأيه: إن أعطاكم ما تريدون فاحتكموه، وإن لم يعطكم حذرتم، فلم تحكموه، فدسوا إلى رسول الله ﷺ ناسا من المنافقين ليخبروا لهم رأي رسول الله ﷺ، فلما جاء رسول الله ﷺ، أخبر الله رسوله بأمرهم كله وما أرادوا، فأنزل الله عز وجل {يا أيها الرسول لا يحزنك الذين يسارعون في الكفر من الذين قالوا آمنا} إلى قوله {ومن لم يحكم بما أنزل الله فأولئك هم الفاسقون} ثم قال فيهما: والله نزلت، وإياهما عنى الله عز وجل.