'Seed of Abraham' in the Bible

Neither, because they are the seed of Abraham, are they all children: but, In Isaac shall thy seed be called.

I say then, Hath God cast away 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 verily he took not on him the nature of angels; but he took on him the seed of Abraham.