Look Osiris I will provide another scripture as reference, this time as you wanted for the spiritual seed of Abraham...it is this and it should suffice.
Galatians 3:16 — King James Version (KJV 1900)
16 Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.
or
Galatians 3:16 — New American Standard Bible: 1995 Update (NASB95)
16 Now the promises were spoken to Abraham and to his seed. He does not say, “And to seeds,” as referring to many, but rather to one, “And to your seed,” that is, Christ.
Galatians 3:29
And if you are Christ’s, then you are Abraham’s offspring, heirs according to promise.
The (singular) Seed of Abraham is Christ.
Scripture does not say ‘and to seeds,’ meaning many people, but ‘and to your seed,’ meaning one person, who is Christ.” The passage goes on to explain that an inheritance was promised to Abraham’s Seed (Christ) apart from the Law. Later, the Mosaic Law was introduced, but it did not annul the promises made to Abraham or to Abraham’s Seed (Christ).
Just as Abraham believed God and his faith was counted as righteousness (
Genesis 15:6), so are all today who believe in God’s Son justified apart from the Law. In this way, Abraham is the “father” of all who believe (
Romans 4:11–17). “If you belong to Christ, then you are Abraham’s seed, and heirs according to the promise” (
Galatians 3:29).
Romans 4:11-17
He received the sign of circumcision as a seal of the righteousness that he had by faith while he was still uncircumcised. The purpose was to make him the father of all who believe without being circumcised, so that righteousness would be counted to them as well, the promise to Abraham and his offspring that he would be heir of the world did not come through the law but through the righteousness of faith. For if it is the adherents of the law who are to be the heirs, faith is null and the promise is void. The law brings wrath, but where there is no law there is no transgression.
In order that the promise may rest on grace and be guaranteed to all his offspring—not only to the adherent of the law but also to the one who shares the faith of Abraham, who is the father of us all, “I have made you the father of many nations”—in the presence of the God in whom he believed, who gives life to the dead and calls into existence the things that do not exist.
Now where is all your scripture, for one, saying that the blood-line Hebrews/Israelite, the physical seed is what Abraham was promised as the seed that are to be saved?
Blessings,
APAK