Abd-Allah ibn Ubayy
Abd-Allah ibn Ubayy (Arabic: عبد الله بن أبي بن سلول, died 631), also called ibn Salul in reference to his mother, was a chief of the Arab tribe Banu Khazraj and one of the leading men of Medina (then known as Yathrib). Upon the arrival of Muhammad, Ibn Ubayy became a Muslim, though the sincerity of that conversion is disputed. Because of repeated conflicts with Muhammad, Islamic tradition has labelled him a Munafiq (hypocrite) and "leader of the Munafiqun".
Position in Medina
Ibn Ubayy was one of the chiefs of the Khazraj, who at his time were in conflict with the other major Arab tribe of the city, the Banu Aws. During the fidjar, the so-called "sacrilegious war", Ibn Ubayy had led parts of the Khazraj tribe on the first day of fighting, but held aloof on the second day. Neither did he participate in the Battle of Bu'ath, due to a quarrel with another leader over the execution of Jewish hostages. It appears that at one point during this conflict, his life was saved by his Jewish allies from the tribe of Banu Qaynuqa, as he would later exclaim: "300 soldiers armed in mail, and 400 unequipped, -- they defended me on the fields of Hadaick and Boath from every foe."
Ibn Ubayy "used every effort to end the fratricidal strife"  and achieved a partial reconciliation between the two factions, which both recognized the leadership of Ibn Ubayy. He occupied a high status in pre-Islamic Medinan society, and his supporters aimed for him to become "king". This aim was not realized, however, due to the arrival of Muhammad in 622: since the tribal conflict was never completely resolved, some citizens looked towards another arbitrator and called in Muhammad, whose preaching had made him famous beyond his home town of Mecca. The arrival of a man who claimed to speak in the name of God eclipsed Ibn Ubayy's influence. This provoked his jealousy, which he was careful to conceal, but was mitigated by his moderation and peacefulness. Ibn Ubayy nonetheless remained a well-respected man. According to Ibn Ishaq, Ibn Ubayy was "a man of great authority in Medina before the advent of the apostle" and "remained a continuing thorn in the flesh of his success." 
After the entry of Muhammad in Medina, large parts of the Arab population converted to Islam. Ibn Ubayy followed suit, according to Maxime Rodinson, as "he thought it wiser to join than to stand out against it." However, Rudi Paret thinks it probable that he converted very soon after Muhammad's Hijra, at the same time as Sa'd ibn Mua'dh. Islamic tradition, which views Ibn Ubayy's conversion as insincere, labelled him "leader of the hypocrites" (munafiqun). However, according to Rodinson, Ibn Ubayy may have converted out of a "genuine sympathy with monotheist ideas fostered by his friendly relations with the Jews."
Being second only to Muhammad, Ibn Ubayy became a "figurehead for those Arabs of Medina who, openly or secretly, sneered at the Prophet's teaching and complained of the confusion and the danger which the coming of the Muslims had brought to Medina" . Ibn Ishaq writes that some of the Ansar "were not altogether convinced of the political wisdom of supporting the apostle: these came to be regarded as paying lip-service to Islam, but hiding treachery in their hearts, and they were known and reviled as 'the Hypocrites'". William Muir opines that tradition "makes a scapegoat of Abdallah" standing for "a great number, who had incurred Mahomet's anger, and some of them much more than Abdallah".
In 624, the Muslims moved against the Jewish tribe of the Banu Qaynuqa and, after a siege of 15 days, eventually forced them to surrender. Now, Ibn Ubayy was allied to the Qaynuqa and according to Muslim historians, appealed to Muhammad for leniency to be shown to them. Ibn Ubayy grabbed hold of the top of Muhammad's breast plate as he turned away, provoking his anger. "Let me go," Muhammad said. Ibn Ubayy replied:
"Nay [...] I will not let thee go, until thou hast compassion on my friends; 300 soldiers armed in mail, and 400 unequipped, -- they defended me on the fields of Hadaick and Boath from every foe. Wilt thou cut them down in one day, O Mahomet? As for me, I am one verily that feareth the vicissitudes of fortune."
After this, Muhammad acceded to his request, and gave the Banu Qaynuqa three days to leave the city.
Ibn Ubayy's last sentence has been interpreted in various ways. Rodinson considered it as threat against Muhammad, while Watt opined that Ibn Ubayy "urged their importance as a fighting unit in view of the expected Meccan onslaught".
Muslims have traditionally seen this episode as another piece of evidence for Ibn Ubayy's hypocrisy, since Ibn Ubayy insisted that adherence to Islam had not completely severed the old obligations of tribal and personal loyalty. However, Ibn Ubayy had not defended the Qaynuqa but merely pleaded for mercy. His plea implies that Muhammad intended to put the Qaynuqa to death, as he later did with the Banu Qurayza, but after Ibn Ubayy's intercession, they were merely expelled from Medina – their property falling to Muhammad and the Muhajirun.
Battle of Uhud
In the consultations preceding the approaching Meccan attack on Medina in 625, Ibn Ubayy had favored Muhammad's original plan to defend from the strongholds inside Medina itself, saying:
"our city is a virgin, inviolate. We have never gone forth to our enemies, but we have suffered loss: remaining within our walls, we have beaten them off with slaughter. Leave the Coreish alone. If they remain, it will be in evil case; when they retire, it will be disappointed and frustrated in their designs."
Some young Muslims, however, argued that the Meccans should be fought outside of the city. Persuaded by the latter, Muhammad adopted an offensive strategy.
According to al-Waqidi, Ibn Ubayy also marched out with 300 of his own men and his remaining Jewish allies, but Muhammad ordered him to send the Jews back into the town, calling them "idolaters". Muhammad resumed his advance, while Ibn Ubayy led his men back to Medina, retiring to the strongholds. According to Islamic tradition, he expressed his anger about his advice being rejected, proclaiming: "We do not know why we shall kill ourselves". It has also been presumed that Ibn Ubayy turned back to protect the town or his own possessions. According to Watt, Surah 3:166 interprets Ibn Ubayy's withdrawal as showing "cowardice and lack of belief in God and the Prophet"
Muhammad's 700 men met the 3000 of the Quraish in the Battle of Uhud and were defeated. The Quraish, however, did not succeed in killing Muhammad, nor did they occupy the town of Medina. Rodinson suggests that the Meccans did not want to reforge the very unity of the population, which had been jeopardised by Muhammad's defeat.
Ibn Ubay was also involved in Muhammad's conflict with another Jewish tribe, the Banu Nadir. Ibn Ishaq writes that when Muhammad ordered the tribe to leave the city within ten days, "certain persons of Medina who were not Believers sent a message to the Banu al-Nadir, saying, 'Hold out, and defend yourselves; we shall not surrender you to Muhammad. If you are attacked we shall fight with you and if you are sent away we shall go with you.'" Other sources include or even identify these persons with the Muslim Ibn Ubayy. Waqidi reports that Ibn Ubayy at first strove to bring about a reconciliation, and Tabari relates that Abd-Allah accused Muhammad of treachery and urged the Nadir to resist by promising aid. However, as the promised help failed to materialize, the Nadir surrendered and Muhammad expelled them from the city.
Watt consider this the first instance, in which Ibn Ubayy went beyond verbally criticizing Muhammad to intriguing against him, a practice he sees as continuing for the next two years.
Controversy during the Mustaliq campaign
In 627, Ibn Ubayy participated in a raid against the Banu Mustaliq. On the march home from this campaign, conflict arose between the Muhajirun and the Ansar when a Bedouin servant of Umar pushed an ally of the Khazraj. Hearing of this, Ibn Ubayy reportedly voiced his discontent:
"This ... ye have brought upon yourselves, by inviting these strangers to dwell amongst us. When we return to Medina, the Mightier shall surely expel the Meaner!"
Watt described this phrase as an attempt by Ibn Ubayy "to undermine Muhammad's authority and make men think of expelling him". Muhammad forestalled any fighting by immediately continuing the march. Ibn Ubayy denied having said this and Muhammad accepted this excuse, though after the return to Medina the "Munafiqun" would be reprimanded in Surah 63:8. Reportedly Muhammad rejected the advice of Umar, who counseled to have Ibn Ubayy killed, and also the offer of Ibn Ubayy's own son, a fervent Muslim, to kill his own father.
Later on during the march, Muhammad's wife Aisha was rumoured to have committed adultery and Ibn Ubay was among those spreading the rumour. One of the chiefs of the Aws asked for the permission to punish the slanderers (without incurring a feud), but the Khazraj opposed this. After Muhammad had announced that he had received a revelation confirming Aisha's innocence, he had her accusers punished by eighty lashes but did not venture to enforce the sentence against Ibn Ubayy.
According to Watt, after 627 there is no record of Ibn Ubayy "actively opposing Muhammad or intriguing against him". In 628, Ibn Ubayy participated in the march to Hudaybiyya. According to Rudi Paret, Muhammad's "most dangerous rival" was now on Muhammad's side.
In 630, when Muhammad's launching a campaign against the Byzantine Empire during a time of drought and food shortage created serious discontent in Medina, Ibn Ubayy expressed his sympathy for those criticizing the expedition as untimely. As the army assembled, Ibn Ubayy's troops formed a separate camp and turned back to Medina when Muhammad's forces set out. This possibly happened with Muhammad's consent, because of Ibn Ubayy's ill health. After Muhammad's return, those criticizing the campaign and had remained behind were chided in Surah 9:81.
Ibn Ubayy died two months after Muhammad's return, in 631. Despite the various conflicts between the two men, Muhammad did not show signs of vindictiveness towards Ibn Ubayy, when he attended his funeral and prayed above his grave. With Ibn Ubayy died the faction of the Munafiqun, as "there was no one left [...] possessed of power or influence."
- William Montgomery Watt, "`Abd Allah b. Ubayy", Encyclopaedia of Islam
- John Bagot Glubb, The Life and Times of Muhammad (2002), p. 142
- William Muir, The Life of Mahomet, vol. 3, chapter 13
- Glubb (2002), p. 197f.
- Glubb (2002), p. 161, 164f.
- Maxime Rodinson, Muhammad: Prophet of Islam (2002), p. 156
- Ibn Ishaq, The earliest biography of Muhammad´
- Rudi Paret, Mohammed und der Koran, Stuttgart: Kohlhammer (1957), p. 103.
- Saif-ur-Rahman al-Mubarakpuri, Ar-Raheeq Al-Makhtum (2002), p. 285
- Sayed Ali Asgher Razwy, Restatement of History of Islam
- Rodinson (2002), p. 157
- William Muir, The Life of Mahomet, vol. 3, chapter 14
- Rodinson (2002), p. 173
- Glubb (p. 197) refers to Ubada ibn al-Samit as an alternative; a Muslim from the tribe of Aws and also an ally of the Qunayqa, he renounced his friendship the Jews at this point.
- William Muir, The Life of Mahomet, vol. 3, chapter 14
- al-Mubarakpuri (2002), p. 298
- Glubb (2002), p. 202-205.
- Some scholars interpret this Surah to indicate that Ibn Ubayy stayed in the town in the first place; A. Schaade, "`Abd-Allah b. Ubaiy", Enzyklopädie des Islam.
- Rodinson (2002), p. 182
- William Muir, The Life of Mahomet, vol. 3, chapter 15.
- V. Vacca, "Nadir, Banu'l", Encyclopaedia of Islam
- Hartwig Hirschfeld, "Abdallah ibn Ubaiy", Jewish Encyclopedia.
- William Muir, The Life of Mahomet, vol. 3, chapter 16
- Akram Diya Al-Umari, The Bonds of Faith Are the Bases of the Links Between Men (1991).
- Glubb (2002), p. 262f.
- William Montgomery Watt, "Aisha bint Abi Bakr", Encyclopaedia of Islam
- Glubb (2002), p. 264f.
- Rudi Paret, Mohammed und der Koran, Stuttgart: Kohlhammer (1957), p. 126.
- Glubb (2002), p. 333f.
- Watt, William Montgomery. "'Abd Allah b. Ubayy". In P.J. Bearman, Th. Bianquis, C.E. Bosworth, E. van Donzel and W.P. Heinrichs. Encyclopaedia of Islam Online. Brill Academic Publishers. ISSN 1573-3912.
- Rodinson, Maxime (2002). Muhammad: Prophet of Islam. Tauris Parke Paperbacks. ISBN 1-86064-827-4.
- Glubb, John Bagot (1970 (reprint 2002)). The Life and Times of Muhammad. Hodder & Stoughton. ISBN 0-8154-1176-6.
- al-Mubarakpuri, Saif-ur-Rahman (2002). Ar-Raheeq Al-Makhtum ("The Sealed Nectar"). Riyadh: Darussalam publishers. ISBN 1-59144-071-8.