'Seed of Abraham' in the Bible

nor, because they are the seed of Abraham, are they all children: but, in Isaac shall thy seed be called.

I SAY then, Hath God rejected his people? God forbid. For I also am an Israelite, of the seed of Abraham, of the tribe of Benjamin.

Are they Hebrews? so am I. Are they Israelites? so am I. Are they the seed of Abraham? so am I.

For he verily took not on him the angelic nature, but assumed that of the seed of Abraham.