Just insist on the correct lineage; Abraham, Isaac, and Jacob when one wants to designate a Jew
But here is the important thing- you and I both respect the Bible and that's great. From your handle I assume you are a Vet, so thank you, buddy. Have a good one.
Actually, if we’re going to get all technical, after Sarah died Abraham had six more sons with Keturah. And quite probably some daughters.