The Jewish Encyclopedia,1925 edition, vol. 5, p. 41, says:"Edom is in ModernJewery." The Esau-Edomite nation ... "Thus dwelt Esau in Mount Seir; Esau is Edom."
"....Verse 26 has been the center of much discussion: "And so all Israel will be saved ..."
If you just concentrated on this statement, without the aid of any context, your conclusion might be: Paul is saying that every single Jew will eventually be saved! Indeed, this is the interpretation followed by teachers of premillennialism. They talk about the "final restoration of Israel;" that before Christ establishes His kingdom on earth the Jews will be restored to their former position as God's chosen people and all of them will be saved. They cite this verse as proof.
Of course, the whole premillennial program is in error; it conflicts and clashes with scripture on a number of points, chief of which is the fact that the kingdom has already been set up, and Christ is now reigning. But when premillennial teachers speak of the "final restoration of Israel," they cite Romans 11:26 -- "And so all Israel will be saved." And just the statement, without context, may seem to say this, that every single person who is a Jew will eventually be saved.
But - this cannot be what Paul is saying, because all through these three chapters he has argued JUST THE OPPOSITE. God doesn't confer salvation on nations, but on individuals who choose to obey Christ, Jew or Gentile. Remember "WHOSOEVER" calls upon the name of the Lord, shall be saved, or as explained back in chapter 6 - those persons who obey from the heart that form of doctrine (the gospel) --- THOSE INDIVIDUALS ARE SAVED. So God doesn't accept and save somebody, by virtue of their race: "ALL ISRAEL WILL BE SAVED" cannot mean that.
But further, if this meant the eventual salvation of every single Jew, that would make God a respecter of persons; it would make Him partial to a people due to their genealogical background. In the house of Cornelius, Paul said: "In truth I perceive that God shows no partiality. But in every nation whosoever fears Him and works righteousness is accepted by Him," (Acts 10:34,35).
For these reasons we just cannot accept the interpretation that this phrase means -- God will eventually save every single Jew. Here is an approach to this phrase that is supported by the context. Sometimes, this little word "so" is equal to "therefore," -- it introduces a conclusion. But, not always !! Those with scholarly credentials in Greek tell us, the word is sometimes an adverb of manner meaning, in the same way, or in like manner.
I believe this is the way the word is used, in Rom. 11:26. I don't think Paul is stating a conclusion; I think he is saying -- all, of Israelite blood who are saved will be saved IN THE SAME MANNER AS THE GENTILES !! This phrase does not teach the eventual salvation of every Israelite. It teaches that all Jews who are saved will be saved in the same manner as anybody else --- by responding to Christ (obeying the gospel).
A good parallel passage: "But we believe that through the grace of the Lord Jesus Christ, we shall be saved in the same manner as they," (Acts 15:11). ......"