ibn Dinar, from Sa'id ibn Jubayr regarding the saying of Allah: "Those" - meaning: those who did what Allah mentioned in this verse, "are the ones who have been true" - meaning: the righteous (al-muttaqun).
His saying: "O you who have believed"
Its interpretation has already been provided.
His saying: "Prescribed for you is legal retribution (qisas) for those murdered"
1573 - Yunus ibn 'Abd al-A'la informed us by reading, Sufyan ibn 'Uyaynah narrated to us, from 'Amr - meaning Ibn Dinar - from Mujahid, from Ibn 'Abbas, he said: There was legal retribution (qisas) among the Children of Israel, but blood money (diyah) was not among them. So Allah, Mighty and Majestic is He, said to this nation: "Prescribed for you is legal retribution for those murdered."
1574 - Abu Zur'ah narrated to us, Yahya ibn 'Abd Allah narrated to us, Ibn Lahi'ah narrated to me, 'Ata' narrated to me, from Sa'id regarding the saying of Allah: "O you who have believed, prescribed for you is legal retribution for those murdered" - meaning: when it is intentional.
It was reported from al-Hasan similarly.
1575 - Al-Hasan ibn 'Abd Allah al-Kufi al-Wasiti narrated to us, al-Nadr ibn Shumayl informed us, Shu'bah informed us, from Mughirah, from al-Sha'bi: "Prescribed for you is legal retribution for those murdered, the free for the free and the slave for the slave" - he said: This was regarding 'ammiyyah (tribal strife/blind fitna), something that existed during the time of the Messenger of Allah, may Allah bless him and grant him peace.
His saying: "The free for the free"
1576 - Abu Zur'ah narrated to us, Yahya narrated to us, Ibn Lahi'ah narrated to me, 'Ata' narrated to me, from Sa'id regarding the saying of Allah the Exalted: "O you who have believed, prescribed for you is legal retribution for those murdered" - meaning: when it is intentional. "The free for the free," and that is because two clans from the Arabs fought during the Age of Ignorance (Jahiliyyah) shortly before Islam. There was killing and wounding between them until they killed slaves and women, and they did not take [retribution] from one another until they accepted Islam. One of the two clans would boast over the other in number and wealth.
(1). Al-'ammiyyah: i.e., the civil strife (fitnah).