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 the Prophet Muhammad in Medina, many of the Arabs 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 the 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 Muhammad's anger, and some of them much more than Abdallah". In 624, the Muslims moved against the Jewish tribe of the Banu Qaynuqa. According to Ibn Hisham, a dispute had broken out between the Muslims and the Banu Qaynuqa, the allies of the Khazraj tribe. When a Muslim woman visited a jeweler's shop in the Qaynuqa marketplace, she was pestered to uncover her face. The goldsmith, a Jew, pinned her clothing such that upon getting up, she was unveiled. A Muslim man, coming upon the resulting commotion, killed the shopkeeper in retaliation and was in turn killed by Jews. As a result of the revenge killings, enmity grew between Muslims and the Banu Qaynuqa. The Muslims besieged the Banu Qaynuqa, and after 15 days, forced them to surrender.