Banu Qaynuqa
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.
Read more about this topic: Abd-Allah Ibn Ubayy