The early part of the Koran came into being when Muhammad lived in Mecca, a city with very few Jews and Jewish tribes. At that time, he presented himself to the Meccans as a Jewish prophet based on the stories he had learned from the Jews he had learned during his travels - and from his cousin Waraqa to a converted Jew (The Koran actually refers to this charge , But "Allah" denies it).
When Muhammad moved to Medina there were already three Jewish tribes, whose good graces he first needed, because he and his small bonds of Muslim immigrants were too weak. He tried to convince these Jews that he was the last in the succession of their own prophets and even changed the Qibla (prayer direction) to Jerusalem, the center of the Jewish world.
The Jews in Medina were not impressed by the esoteric assertions of Muhammad, especially since there were obvious discrepancies between their Torah and his version of the same stories. (In the Koran, the Bible is immature in the Bible and sounds more like a series of fairy tales with the same superfluous morality - believing Muhammad's claims about himself or experiencing earthly destruction and eternal torment).
When he was asked why he had no proof of his prophethood by performing miracles like the prophets of the past, Muhammad came up with a prudent apology that there was no point in the past since the Jews were prophets anyway (Koran 3:183-184). Thus Muhammad had nothing to offer but his own testimony.
The Prophet of Islam did not treat the Jewish rejection well, especially since his people had relied heavily on his many claims to be a prophet in the same way like Moses, Abraham and Jesus. Muhammad "solved" his dilemma by claiming that the Jews of Medina were heretics, and that his version of the Torah is a fake, since it "did not contain the verses" that supported his claims to be a prophet. (Interestingly, in spite of the many Jews, who were either converted to Islam from either compulsion or free will, the "unadulterated" Torah never came to light, which supposedly existed).
After Muhammad's victory against the Meccans in Badr, his wealth and power was so far that he could take care of his "Jewish problem". The words of the Koran are markedly harder to the "people of the book" in the Medina part of the text, and it goes into confrontation.
Much got done by the "constitution" of Medina, but the treaty that Muhammad created for all local tribes upon his arrival got temporarily forgotten. The Muslims have often forgotten to cancel or annul a contract. However, this contract got canceled after less than two years:
While we were in the Mosque, the Prophet came out and said, "Let us go to the Jews" We went out till we reached Bait-ul-Midras. He said to them, "If you embrace Islam, you will be safe. You should know that the earth belongs to Allah and His Apostle, and I want to expel you from this land. So, if anyone amongst you owns some property, he is permitted to sell it, otherwise you should know that the Earth belongs to Allah and His Apostle." (Bukhari 53:392)
After announcing his intentions, Muhammad sought an apology to take land from those Jews who refused to convert to Islam. His first goal was a tribe that had recently been in a conflict with the other two. Muhammad has correctly advised that the two other Jewish tribes would not come to support the Banu Qaynuqa tribe during a siege.
Muhammad's excuse has been an incident in which a Muslim was killed by the angry Jewish mob. The fact that the mob was furious because the Muslim in question had just murdered a Jewish merchant for the honor of a woman is sometimes denied by contemporary advocates of Islam who nevertheless admit that Muhammad decided to siege the Qaynuqa fort instead of his peaceful determination To agitation.
This point is important. According to Muslim historians, the first blood shed was when a Jew was murdered by a Muslim for playing a prank on a Muslim woman (by lifting her dress). The Muslim was killed in retaliation by those who had just witnessed the murder.
On what basis is physical violence - much less murder - justified by such a prank? Moreover, if Muhammad believed in the Old Testament law of the "eye for eye," why did he not recognize the legitimacy of the second killing against the inequality of the first?
In any case, the self-proclaimed prophet of God answered with a self-serving power against a people who had taken him into their community less than two years earlier. Unprepared for the battle, the Qaynuqa surrendered to their former guest without fighting.
Muhammad wanted to kill the entire tribe, but this was ruined by an Arab friend who was horrified by his intentions:
Abdullah b. Ubayy b. Salul went to him when God had put them in his power and said, "O Muhammad, deal kindly with my clients" (now they were allies of Khazraj), but the apostle put him off. He repeated the words, and the apostle turned away from him, whereupon he thrust his hand into the collar of the apostle's robe; the apostle was so angry that his face became almost black.
He said, "Confound you, let me go."
He answered, "No, by God, I will not let you go until you deal kindly with my clients. Four hundred men without mail and three hundred mailed protected me from all mine enemies; would you cut them down in one morning? By God, I am a man who fears that circumstances may change"
The apostle said, “You can have them.” (Ibn Ishaq/Hisham 546)
Muhammad allowed the Jews of Qaynuqa to escape with what they could carry. He confiscated their wealth and their land, took a fifth for himself and gave the remaining to the rest of the Muslims. (According to the Koran, this was their punishment for those who do not believe in Muhammad. 3:10-12)
The man who saved the lives of the Jews was later called from Muhammad to be a hypocrite, and it is obvious that he deeply regretted his decision not to kill the Qaynuqa. One of the nine Koranic verses, which forbids Muslims taking Jews and Christians as friends, was "revealed" at this time.
Thus, Muhammad was able to fulfill his own promise that "Those who oppose Allah and His Messenger (Muhammad), they will be among the lowest (most humiliated)." (Koran 58:20), further strengthening his credibility among the Muslims and inspiring fourteen centuries of unrelenting jihad in his name to his followers.