And so -- Paul comes to a summary of his point about how the Jews and Gentiles will be saved the same way, by the gospel of grace, Romans 11:5-6.
And so -- Adverb, "thusly", in this way, on this fashion, that is, they must be saved by the Gospel also. "in this manner" Lenski. "So" houtos as in verse 5, Romans 11:5; Romans 11:26; Romans 11:31. The ESV correctly translates this adverb.
so -- G3779 houto Thayer Definition: in this manner, thus, so. Part of Speech: adverb.
And so -- By Jews and Gentiles being grafted into the same root, all Israel, Jew and Gentile, will be saved.
all Israel will be saved -- All Israel that is saved will be saved in this way, that is, by the gospel of Christ. The same gospel that saves the Gentiles.
In v. 25 we have a reference to physical Israel, but in this verse (v.26) we have a different usage of the term "Israel" which is shown by the phrase "all Israel."
all Israel -- This ... could refer to Israel as symbolic of God’s elect—all who are now part of God’s people (both Jews and Gentiles) - FSB
The phrase all Israel could refer to the total of all believers, both Jewish and Gentile; with this meaning, and so would describe the way that God works to bring salvation to all his people. - NLTSB
This [Israel] refers in some sense to spiritual Israel, the Church. Paul used this concept in Galatians 6:16 - Utley
God saves all his elect people, both Jews and Gentiles, as they respond in faith to God’s grace throughout history. “Israel” would then refer to the church (see Galatians 6:16 and note for this possibility). - NIVZSB
Paul answers who the real Israel is in
Romans 2:28-29; Romans 4:12-14; Romans 9:4-8; Galatians 3:27-29; Israel, is the spiritual descendants of Abraham, both Jews and Gentiles.
Considering Romans 9:6 "Israel" is all of God’s people today. So, "all Israel" in v. 26 is both Jews and Gentiles. In Romans 11:14, Paul wants "some saved" but in v. 26 "all Israel" we see the fulfillment of Paul’s illustration where the natural olive branch (Jews) being grafted back in with the wild branch (the Gentiles) and all receiving their nourishment from the true root, being now "all Israel." In this manner "all Israel" (both Jews and Gentiles), the church, will be saved. (Note from A.B. class.)
all Israel shall be saved -- To use this verse to teach that all Jews will be saved is to miss the context. Paul’s message is that now in the covenant of grace all Jews (Israel) who will be saved will be saved on the same condition as everyone else, by their faith and obedience to the Gospel of Christ.
as it is written -- Isaiah 59:20. The quotation is not literally made, but the sense of the passage is preserved. The Hebrew is, “There shall come to Zion a Redeemer, and for those who turn from ungodliness in Jacob.” There can be no doubt that Isaiah refers here to the times of the gospel.
out of Zion -- Refers to Jerusalem, and here to Judaism by extension. A prophecy of Christ coming to bring back "Jacob" to the Lord.
The mechanism of salvation will be faith in Jesus the Messiah. - Utley