3 For I could wish that I myself were accursed—cut off from Christ—for the sake of my people, my fellow countrymen, 4 who are Israelites. To them belong the adoption as sons, the glory, the covenants, the giving of the law, the temple worship, and the promises. 5 To them belong the patriarchs, and from them, by human descent, came the Christ, who is God over all, blessed forever! Amen. 6 It is not as though the word of God had failed. For not all those who are descended from Israel are truly Israel, 7 nor are all the children Abraham’s true descendants; rather “through Isaac will your descendants be counted.” 8 This means it is not the children of the flesh who are the children of God; rather, the children of promise are counted as descendants.
Kiddushin 36aBabylonian Talmud
The Gemara further asks: And what is the reason that Abaye did not state the same reason as Rava? The Gemara answers that Abaye could have said to you: Phylacteries themselves are derived from here, i.e., the meaning of the phrase “between your eyes” stated with regard to phylacteries is understood from the case of baldness: Just as there, with regard to a bald spot, “between your eyes” is referring to a place where baldness is formed, a spot where there is hair, which is on the upper part of the head but not actually between the eyes, so too, the place where phylacteries are donned is on the upper part of the head. The Gemara asks: And both Abaye and Rava, what do they derive from this verse: “You are the sons to the Lord your God” (Deuteronomy 14:1)? According to the first explanation of Isi’s opinion, the exclusion of women is derived from this phrase, whereas they derive that halakha from a different source. The Gemara answers: This verse is necessary for that which is taught in a baraita: The verse: “You are the sons to the Lord your God,” indicates that when you act like sons and cleave to the Holy One, Blessed be He, you are called sons, but when you do not act like sons you are not called sons. This is the statement of Rabbi Yehuda.
Notes and References
"... This completes the explicit statement of the problem [Paul] is dealing with in Chapters 9-11 — 'In the case of the Jews, has the Word of God failed?' (see 9:1-11:36). But the question is raised in a way that anticipates the happy conclusion, 'No, it has not failed.' ... Here, where his focus is on the Jewish nation as a whole, in its capacity as God's people, Israel (on this important term, see ll:26), he introduces the concept of the faithful 'remnant,' an idea which pervades the Tanakh (see verses 27-28, 11:1-6). In fact, the Tanakh warns that in certain cases of disobedience a person may be 'cut off from among his people' (see Acts 13:38-39). That the notion was accepted in non-Messianic Judaism can be inferred from the fact that in the Mishna the well-known statement, 'All Israel has a place in the world to come,' (Sanhedrin 10:1, quoted more fully at 11:26) is immediately followed by a list of Israelites who have no place in the world to come. It should not be thought that God is quick to cast away his sons, meaning the Jewish people (Exodus 4:22). Keeping in mind 8:14-15, 9:24-25 and 11:1-6, consider this passage from the Talmud (Kiddushin 36a) ..."
Stern, David H. Jewish New Testament Commentary (p. 389) Jewish New Testament Publications, 1994