The Bible is clear that God promised that the descendants of Ishmael would be many.

But the heirs of Abraham are the descendants of Isaac. They are the Jews that the land of Israel has been promised.

It is through Isaac that the promises of the land and the coming Messiah would be fulfilled.

The Bible is also clear that it is not the descendants of Ishmael who are to be heirs to the land, but to the descendants of Isaac.