Ishmaelism in this more limited definition holds that Ishmael was both an important religious figure and eponymous ancestor for some of the Arabs of western Arabia . Prominence is given in Arab genealogical accounts to the first two of Ishmael 's twelve sons , Nebaioth ( Arabic : نبيت , Nabīt ) and Qedar ( Arabic : قيدار , Qaydār ) , who are also prominently featured in the Genesis account . It is likely that they and their tribes lived in northwestern Arabia and were historically the most important of the twelve Ishamelite tribes .