This is likely referring to the Banu Qaynuqa (بنو قينقاع) which was one of the three Jewish Tribes in Medina. However, Banu Qaynuqa was expelled for allegations of military treason (which would violate the Medinan Constitution). They were not expelled for resisting the message of Islam. Conversely, the Banu Nadir (نو النضير) (another Jewish Tribe) did flee Medina after Muhammad ordered the expulsion of Banu Qaynuqa and slaughtered the males of Banu Qurayza (بنو قريظة) (the final Jewish Tribe) since they refused to convert and did not want to be similarly slaughtered.