[aruanan]

Sorry, but genetic evidence links Arab and Jewish populations as both being of Semitic origin (Science confirms Biblical linkage). And the Bible says from Genesis 21....

No. This is still at too general a level. More specifically, if Abraham indeed was the founder of both the Jewish and the Arab groups, there would be a very close link between them. Such a specific link does not exist. The closest in genetic lineage with Middle Eastern Jews are certain non-Arab groups in the Mesopotamian region, not Arabs. And the Bible passage you quoted says nothing about Arabs being descended from Abraham.

[allmendream]

Well then, what “great nation” was founded by Ishmael as God promised? Both Arab and Jewish tradition holds that Ishmael founded the Arab nation. The Bible doesn’t say “Arab” but it mentions a place, and that place was Arabia. The Bible doesn’t mention a nation, but the nation of people that live in Arabia is Arabian.