At the time when Prophet Muhammad emigrated to Madina, virtually half of the city’s population consisted of Jews from the Banu Nadir, Banu Qaynuqa and Banu Qurayza tribes.
It is not known for certain when the Jews began to settle in the Arabian Peninsula or, more specifically, in Madina. There are also views holding that the Jews in the Arabian Peninsula did not come from outside, but were Arabs who had accepted Judaism. It is generally accepted that they came to the Peninsula from abroad; however, there are differing views on the exact time of their arrival. According to some narrations, Jews that had been expelled from Palestine following either the Babylonian King Nebuchadnezzar II’s (605–562 BC) occupation of Jerusalem and the subsequent destruction of the Temple of Solomon, or in later attacks, settled in various regions of the Arabian Peninsula such as the Hejaz, Wadi al-Qura', Khaybar, Tayma, Yathrib and Ayla. Those who came to in Yathrib first settled in city’s outskirts, and later increasing in strength expelled the Amaliqa and Jurhum tribes residing therein and like so gained control of the city.
Following the Great Flood (Sayl al-‘Arim) in Yemen during the second century AD, leader of the ‘Azd branch of the Qahtani tribes, Harith ibn Tha'laba ibn 'Amr Muzaykiya, emigrated from Yemen with his tribe and settled in the outskirts of Yathrib; over time, his descendants, the Aws and Khazraj tribes gained ascendancy over the Jews and gained control of the city. Losing their dominance to the Aws and Khazraj, the Jewish tribes continued their existence in the region, with some siding with the Aws and others with the Khazraj in disputes that arose between them. In the Battle of Bu’ath for instance, which broke out five years before the Emigration (617 AD), the Banu Qurayza and Banu Nadir Jews formed allied with the Aws while the Banu Qaynuqa sided with the Khazraj; the ensuing battle ended with the defeat of the Khazraj. On the other hand, there were also various disputes and conflicts between the Banu Qaynuqa and the other Jewish tribes.
In contrast to the situation in the political arena, the Jewish tribes were much more influential than the Arab tribes economically. Agriculture, trade, ironworking, arms manufacture, textiles, and jewelry making were all in the hands of the Jewish tribes. The Banu Qaynuqa was famous for jewelry-making, the Banu Nadir in agriculture, and the Banu Qurayza in the leather trade. The Jewish tribes had become wealthy by participating in trade fairs, and when they could not collect the money that they had loaned with interest, they would impound the assets and estates of debtors and as such began to live in prosperity. In addition, there were also those who made money from fortune telling and soothsaying. The Jews also owned an education and teaching center (Bayt al-Midras) in Madina. It is known that Prophet Muhammad and some of his Companions visited this center for the purpose of conveying the message of Islam.
The Banu Qaynuqa, who resided in Madina’s southwest, lived in fortresses (utum) which were found throughout the city. Known among Madina’s Jewish tribes for its bravery and militancy, the Banu Qaynuqa made its living from trade, arms manufacture and jewelry-making in particular. For this reason, they did not possess agricultural land. They owned a marketplace in Madina called the Suq al-Banu Qaynuqa, used by both Jews and Muslims. It was due to these activities that the Banu Qaynuqa were wealthier than the other Jewish tribes.
The Banu Qaynuqa Jews joined the pact that Prophet Muhammad made with Madina’s Arab and Jewish tribes, known as the constitution of Madina, as an ally of the Khazraj tribe. With this pact, it was envisaged that in the event of any attack on Madina, the Jewish tribes too would join the defense – with an attack on any tribe being considered an attack on all the others and all parties responding in unison – and that, furthermore, the Jews would not side with the Quraysh or the other enemies of the Muslims.
The attitude that Prophet Muhammad adopted towards the Jews in Madina yielded certain positive results, with one of the prominent scholars of the Banu Qaynuqa ‘Abd Allah ibn Salam and his family accepting Islam. However, despite threatening members of the Aws and the Khazraj with their assertions that they would follow the Prophet to appear in the near future and that they would thus gain an advantage over his enemies, they refused to accept the Prophethood of Prophet Muhammad because he was not from among them. Furthermore, they took particular steps in order to turn Muslims away from their religion, from time to time mocking the Qur’an and the Prophet. Dredging up the old rivalry and hostility between the Aws and the Khazraj, they attempted to cause dissension, thus inciting the hypocrites. Some of them stated that they accepted Islam, but joined the ranks of the hypocrites. The Muslims’ triumph over the Makkan polytheists at the Battle of Badr, despite their small numbers, disturbed the Jews. They made their annoyance clear in various ways and began creating uproar. Gathering the Jews at the Banu Qaynuqa market in response, the Prophet Muhammad told them that he was a Messenger sent by God and that they ought to take lesson from all that befall the Qurasyh; the Prophet asked them to asked Islam. However, the Jews had the audacity to suggest that the Prophet not be deceived by his victory over the Quraysh who had little understanding of the art of war, and that he would see what war really was and how fierce an enemy they were if they were to fight against them. There are accounts which state that the Qur’anic verses revealing that the disbelievers would shortly be defeated with the help of God by drawing attention to the Battle of Badr were revealed in relation to this response of the Banu Qaynuqa:
While this tension continued, an incident occurring in the Banu Qaynuqa marketplace proved to be the final straw. A Muslim woman from the Helpers who went to a jeweler in the market was harassed by those Jews present there. Upon the woman’s calling for help, another Muslims rushed to her aid and, unable to contain himself, attacked and killed the Jewish jeweler – a member of the Banu Qaynuqa. The Jews then killed this man. Demonstrating the insignificance and present invalidity of the pact signed earlier, this incident simultaneously weighed very heavily on Prophet Muhammad and the Muslims. The Prophet began to feel concern that the Banu Qaynuqa, the first among the Jewish tribes to violate the pact, could behave treacherously at any time. Upon this, the verse declaring that should the Prophet have strong reason to fear treachery from those with whom he had treaty, he could publicly dissolve the pact was revealed (An-Anfal, 5:58).
Twenty months after the Emigration, from mid-Shawwal onwards, Prophet Muhammad laid siege to the quarter where the Banu Qaynuqa resided, appointing Abu Lubaba ibn Abd al-Mundhir as his deputy. The Prophet himself wore the armor, known as Zat al-Fudul, and handed the white standard to his uncle Hamza ibn ‘Abd al-Muttalib. While no combat occurred nor any arrow drawn in the siege that lasted fifteen days up until the beginning of Dhu al-Qa'dah, the Banu Qaynuqa Jews were compelled to surrender when they remained shut-off in their fortresses and all their connections with the outside world completely severed; they also consented to the ruling that the Prophet – who refused their request to be released – was to make (2 Dhu al-Qa'dah/April 642). Upon the Prophet’s deciding that the male warriors among the prisoners of war – said to number around 700 – were to be put to death, leader of the Khazraj, 'Abd Allah ibn Ubayy ibn Salul, declared that the Banu Qaynuqa were their allies, that they had helped them, especially during the Battle of Bu’ath, and asked that the Prophet forgive them. Although Prophet Muhammad knew that 'Abd Allah ibn Ubayy was the leader of the hypocrites, in the face of his persistent petitions, he revoked his decision for the men to be killed and ordered that all the Banu Qaynuqa be expelled from Madina, leaving their possessions behind to the Muslims. Giving the Banu Qaynuqa a period of three days to vacate the city, the Prophet assigned Muhammad ibn Maslama to receive their possessions and 'Ubada ibn Samit to oversee their departure until they were well away from the city. In the meantime, upon the Banu Qaynuqa’s request, they were granted permission to collect their debts. The Prophet also stated that the Banu Qaynuqa could always come to Madina to carry out their business and stay therein for up to three days. Leaving a great many armaments and materials for arms manufacture behind them, the Banu Qaynuqa left Madina under the watchful eye of 'Ubada ibn Samit. After staying in Wadi al-Qura' for a month, they later went to Syria and settled along the Syrian border.
After taking three swords, three spears, two suits of armor and two bows, and one-fifth of the war spoils (khumus), Prophet Muhammad divided the remaining four-fifths among the Muslims. He also gave a suit of armor each to Muhammad ibn Maslama and Sa'd ibn Mu'adh. While there are debates concerning when khumus was first implemented in Islamic history, there are views to the effect of its first being applied during the distribution of war spoils from the Banu Qaynuqa campaign. However, with due consideration to narrations regarding the earlier expedition of ‘Abd Allah ibn Jahsh and the distribution of spoils from the Battle of Badr, it is accepted that khumus was previously applied according to existing traditions and that its first application after the revelation of the relevant Qur’anic verse (An-Anfal, 8:41) was after the Banu Qaynuqa campaign.
One of the significant problems that Prophet Muhammad experienced while in Madina was the dissension created by a band of hypocrites. Leading the group of those pretending to be Muslim despite not believing in Islam or in the Prophethood of Muhammad was 'Abd Allah ibn Ubayy ibn Salul. Chieftain of the Khazraj, 'Abd Allah ibn Ubayy was promised control of Madina at the cessation of hostilities between the Aws and Khazraj tribes, but this had came to nothing when the Prophet emigrated to Madina. It was precisely for this reason that he bore an unending enmity towards the Prophet, lasting until his death. The Jews living in the city and the Makkan polytheists incited this hostility of his. Advising their townspeople against supporting the Emigrants, 'Abd Allah ibn Ubayy together with all the other hypocrites wanted to ensure that they left the city. The hypocrites were always in favor of dissension in the many incidents that arose in the Madinan period and attempted ceaselessly to weaken the solidarity of the Muslims. The sixty-third chapter of the Qur’an, entitled The Hypocrites, was revealed in relation to this faction and those similar ones.