Abbas - Tanwîr al-Miqbâs min Tafsîr Ibn ‘Abbâs
(And when We made with you a covenant) in the Book: (shed not the blood of your people) do not kill one another (nor turn your people) i.e. one another (out of your dwellings) from your homes, meaning: the Banu Qurayzah and Banu'l-Nadir. (Then ye ratified (Our covenant)) you agreed to it (and ye were witnesses (thereto)) while knowing what you were doing.
And when We made a covenant with you, and We said: ‘You shall not shed your own blood, spilling it by slaying one another; neither expel your own from your habitations’: let no one of you expel the other from his house; then you confirmed it, that is, you accepted this covenant, and you bore witness, upon your own souls.
And when We made a covenant with you: 'Do not shed your own blood, by desiring the abodes and attributes of the soul and by inclining towards its caprices and natures, while abandoning your true life and the specific qualities of your acts for the sake of securing its goals and pleasures; neither expel your selves, your essences since the essence is represented by the self, from your habitations', that is, from your spiritual abodes and the holy gardens. Then you confirmed it, by accepting that [covenant], and you bore witness, to it through your initial states of preparedness and your primordial intellects.
Allah criticized the Jews who lived in Al-Madinah during the time of the Messenger of Allah. They used to suffer, because of the armed conflicts between the tribes of Al-Madinah, Aws and Khazraj. Before Islam, the Aws and Khazraj worshipped idols, and many battles took place between them. There were three Jewish tribes in Al-Madinah at that time, Banu Qaynuqa` and Banu An-Nadir, the allies of the Khazraj, and Banu Qurayzah, who used to be the allies of the Aws. When war erupted between Aws and Khazraj, their Jewish allies would assist them. The Jew would kill his Arab enemy, and sometimes they also killed Jews who were the allies of the other Arab tribe, although the Jews were prohibited from killing each other according to clear religious texts in their Books. They would also drive each other from their homes and loot whatever furniture and money they could. When the war ended, the victorious Jews would release the prisoners from the defeated party, according to the rulings of the Tawrah. This is why Allah said,
(And (remember) when We took your covenant (saying): Shed not the blood of your (people), nor turn out your own people from their dwellings.) meaning, "Do not kill each other, nor expel one another from their homes, nor participate in fighting against them.'' Allah mentioned the word `your own' here, just as He said in another Ayah.
(So turn in repentance to your Creator and kill yourselves, that will be better for you with your Creator) (2:54) because the followers of one religion are just like one soul. Also, the Messenger of Allah said,
(The example of the believers in their kindness, mercy and sympathy to each other is the example of one body, when an organ of it falls ill, the rest of the body rushes to its aid in fever and sleeplessness.) Allah's statement,
ثُمَّ أَقْرَرْتُمْ وَأَنتُمْ تَشْهَدُونَ
(Then, (this) you ratified and (to this) you bore witness.) means, "You testified that you know of the covenant and that you were witnesses to it.''
(After this, it is you who kill one another and drive out a party of you from their homes) "Allah mentioned what they were doing, and that in the Tawrah He had prohibited them from shedding each other's blood, and required them to free their prisoners. Now they were divided into two camps in Al-Madinah, Banu Qaynuqa`, who were the allies of the Khazraj, and An-Nadir and Qurayzah, who were the allies of the Aws. When fighting erupted between Aws and Khazraj, Banu Qaynuqa` would fight along with the Khazraj, while Banu An-Nadir and Qurayzah would fight along with the Aws. Each Jewish camp would fight against their Jewish brethren from the other camp. They would shed each other's blood, although they had the Tawrah with them, and they knew their rights and dues. Meanwhile, the Aws and Khazraj were polytheists who worshipped idols. They did not know about Paradise, the Fire, Resurrection, Divine Books the lawful and prohibited. When the war would end, the Jews would ransom their prisoners and implement the Tawrah. Consequently, Banu Qaynuqa` would ransom their prisoners who were captured by the Aws, while Banu An-Nadir and Qurayzah would ransom their prisoners who were captured by the Khazraj. They would also ask for blood money. During these wars, they would kill whomever (Jews or Arabs) they could, while helping the polytheists against their brethren. Therefore, Allah reminded them of this when He said,
(Then do you believe in a part of the Scripture and reject the rest) This Ayah means, `Do you ransom them according to the rulings of the Tawrah, yet kill them while the Tawrah forbade you from killing them and from expelling them from their homes The Tawrah also commanded that you should not aid the polytheists and those who associate with Allah in the worship against your brethren. You do all this to acquire the life of this world.' I was informed that the behavior of the Jews regarding the Aws and Khazraj was the reason behind revealing these Ayat.''
These noble Ayat criticized the Jews for implementing the Tawrah sometimes and defying it at other times, although they believed in the Tawrah and knew what they were doing was wrong. This is why they should not be trusted to preserve or convey the Tawrah. Further, they should not be believed when it comes to the description of the Messenger of Allah, his coming, his expulsion from his land, and his Hijrah, and the rest of the information that the previous Prophets informed them about him, all of which they hid. The Jews, may they suffer the curse of Allah, hid all of these facts among themselves, and this is why Allah said,
(And Allah is not unaware of what you do. Those are they who have bought the life of this world at the price of the Hereafter) meaning, they prefer this life to the Hereafter. Therefore,
فَلاَ يُخَفَّفُ عَنْهُمُ الْعَذَابُ
(Their torment shall not be lightened) not even for an hour,
وَلاَ هُمْ يُنصَرُونَ
(Nor shall they be helped), and they shall find no helper who will save them from the eternal torment they will suffer, nor shall they find any to grant them refuge from it.
Maududi - Sayyid Abul Ala Maududi - Tafhim al-Qur'an
As a concrete example of this may be cited the strange conduct of the different clans of the Jews, who lived in the neighbourhood of Madinah. Before the migration of the Holy Prophet, they had entered into alliances with the neighbouring Arab clans, Aus and Khazraj. When one Arab clan went to war with the other clan, their respective Jewish allies also went to war against each other. Thus Jews waged war upon Jews, whereas this was clearly against the teachings of their Scriptures which they knowingly violated. But when the Jews of one clan fell into the hands of the other clan as prisoners of war, they would redeem them after taking ransom for them. When they were questioned about this inhuman trade of their own brethren, they tried to justify it, saying that it was allowed by the Scriptures. It is strange that they forgot the same Scriptures which they brazenfacedly violated by going to war against each other. Thus on the one hand, they accepted that part of the Scriptures which allowed ransom for prisoners and, on the other hand, rejected that part which prohibited war against their own brethren in faith.