The passage
      v25a. Paul intends to reveal a truth that will remove any possibility for religious conceit in his Gentile readers.
      v25b-26a. There are three stages to the fulfillment of God's plan of salvation: i] The unbelief of the greater part of the Jewish people; ii] The completion of the gathering in of Gentile believers; iii] The salvation of a representative number of Jews. Paul's focus is on the last of these three truths.
      v26b-27. The quote comes from the Septuagint, Isaiah 59:20-21a, 27:9. The prophecy consists of a promise from God to his historic people Israel. A messiah will emerge from the people of Israel (the incarnation of Jesus) and he will deal with the problem of sin and its obvious consequences. God's eternal promise to his people is that he will "take away their sins."
      v28-29. The favoured position of the Gentiles has been made possible by Israel's rejection of the gospel and as a consequence, God's rejection of Israel. This rejection of Israel is neither complete nor permanent, since It is not in God's nature to go back on his promises.
      v30-31. God has used the disobedience of Israel to channel salvation to the Gentiles and he will use the obedience of the Gentiles to channel salvation to Israel. All this falls within the providential mercy of God.
      v32. All humanity is in rebellion against God, both Jew and Gentile, and we are held to this state of rebellion ("disobedience") by the law. Yet, this confinement to sin ("bound to disobedience") has as its purpose the application of divine mercy, of grace, of mercy to all who believe, both Jew and Gentile.

Religious conceit
      Bigotry is no stranger to any of us. When I was a young student we "prots" would stand on the railway station and make rude gestures toward the "tikes" as the early train took them to school. They would gesture back, of course. And when it came to football, it was always an all-in brawl. Thankfully, that was the limit of it; it never quite reached the horrors of Northern Ireland. As to who started it, I think it started in a garden many years ago.
      We always believe our group has it over all the others. For football teams and the like, a little bit of friendly competition never goes astray. When it comes to the Christian church, well! that's a different matter.
      The disciples thought they had it over their Jewish brethren. In truth though, they had no ground for conceit. Their standing in the sight of God was all of his mercy. They could only be superior to their Jewish brothers and sisters if they had merited God's favour. But, such was not the case. For the present, they were in God's good books, but not because of any worthiness on their part. The people of Israel opposed God's work of salvation through Jesus the Messiah and in that act of disobedience they allowed the obedience (in Christ) of the Gentiles. The obedience of the Gentiles would in turn prompt the obedience of Israel. The day was coming when the disobedience of God's historic people would be forgiven. In all this there was no ground for conceit on the part of the Gentile Christians. Where there is no merit, there can only be mercy.
      It is very easy for us to prop up our own self-worth at the expense of others - to view ourselves as superior, more worthy in the sight of God than other Christian individuals or groups. It's one of the dangers of being human. In truth though, our standing in the sight of God is totally of his grace.
      If our Christian lives are going well, if our church is firing along and making an impact on the lives of individual members and on the local community, then we can only thank the mercy of our God. The last thing we can do is give ourselves a pat on the back. The Lord is the one who moves the mountains. It is also true that we can't really look at others and make any worthwhile assessment of their standing in the sight of God. Assessing the spirituality of others is a most dangerous activity. We need always to judge ourselves rather than busy ourselves gauging the worthiness of others.
      Conceit, religious superiority, must not take root among us. If it is true that we are the Lord's people, that we are at this moment being blessed, then it is not by any worthiness on our part, but it is by God's grace, by his mercy.

v25
      gar "-" - for. Paul now establishes the point "how much more readily will these, the natural branches, be grafted into their own olive tree." Of course, the debate is whether Paul goes on to speak of an ingrafting of the nation Israel, or of a representative Israel, and whether this ingrafting is "now", or in the future.
      iJna mh + subj. "So that [you may] not [be conceited]" - lest. Introducing a purpose clause. "Lest you be wise in your own eyes.", "wise in your own conceits", RSV.
      to musthrion (on) "mystery". A mystery in the New Testament is revealed truth for those who have their eyes open, a truth once hidden and now revealed.
      gegonen (ginomai) perf. "has experienced" - has happened. "A hardening has come upon Israel", NRSV.
      pwrwsiV (iV ewV) "a hardening" - hardness. Used of callusing, so of the dulling of spiritual perception. Israel's disobedience entailed rebellion against God, in particular, unbelief.
      apo merouV (oV) "in part". Not all of Israel is unbelieving. Possibly a partial hardening, but unlikely. "Is not permanent", TEV; "partial blindness", NEB.
      acri ouJ "until [the full number of the Gentiles has come in]" until. Prepositional phrase. The unbelief of Israel is temporary and awaits the merciful discretion of God. The New Testament describes the present as a period of delay, of God being patient so that "all" may be saved."
      to plhrwma (a atoV) "the full number" - fullness [of the Gentiles]. The NIV "full number" agrees with most translators who go with the Jewish idea of a particular number of righteous Israelites who will be saved. Paul is obviously applying this idea to the Gentiles, "full quota", Williams. A generalization may be more appropriate since this is likely a technical concept rather than an actual truth, "until the Gentiles have been admitted in full strength" REB. Paul is speaking of the full incorporation of the Gentiles. Of course, this incorporation is ultimately by grace through faith. The idea illustrates divine grace rather than a set number of believers.

v26
      kai ouJtwV "and so" - and thus, so. Possibly just indicating a step in the argument, but more likely linking the salvation of Israel with the "hardening in part until ..."
      paV Israhl "all Israel" The "all" is representative, and "Israel" is better understood as "spiritual Israel" rather than the Zionist state of Israel. Spiritual Israel, in a representative sense, will be restored to the Lord, but not necessarily every Israelite.
      hJxei (hJcw) fut. "come". The following preposition is commonly "from", as NIV, or "out of". Probably referring to the incarnation, of the messiah coming out of the people of Israel, but possibly referring to the parousia where Jesus comes out of heaven, so Cranfield.
      Siwn "Zion". Here it probably means the earthly city of Jerusalem as representing the people of Israel, but heaven is a possibility.
      apostreyei (apostrefw) fut. "he will turn [godlessness] away [from Jacob]" He will take ungodliness (sin = rebellion against God) from the people of Israel. "He will drive all godlessness from Jacob (the Jewish people)", Barclay.

v27
      par emou "my [covenant]" - from, by me. "The covenant from me", Charmerlain, ie. in the sense of authorship where the preposition takes the sense of movement from beside someone, here God as the author of the covenant.
      afelwmai (afairew) aor. subj. "I take away" - The subjunctive forming a temporal clause with the conjunction. The sense is "remove".

v28
      kata + acc. "as far as" - with reference to, in relation to.
      ecqroi adj. "they are enemies" - enemies. They didn't accept the gospel and therefore came under the wrath of God. "Enemies of God", NEB, rather than "hostile toward God."
      di uJmaV "on your account" - because of you. ie. With a view to the advantage of. The punishment of Israel for their rejection of Jesus, serves, in the providence of God, to benefit the Gentiles.
      de "but". Adversative sense. Although punished, yet beloved of God. This is a central point in Paul's argument.
      thn ekloghn (h) "election" - the choice, election. Again, we are faced with the "Calvanist/Arminian" issue. The election of the nation of Israel is surely intended here, not the election of individuals for salvation.
      dia + acc. "on account of" - because of, by reason of. God is faithful to those he chooses to love. There is no ground for it. He has just chosen to love the family of Abraham and therefore, he will not withdraw that love. Such will always be so. "Because of their forefathers", Williams.

v29
      gar "for" - Introducing a reason for the statements in v28.
      ta carismata kai hJ klhsiV "[Gods] gifts and his call" - the gifts and the call. Possibly a hendiadys where a single idea is expressed by two separate words joined by "and". "It is not in God's nature to go back on his covenantal promises."
      ametamelhta adj. "are irrevocable" - "Something one does not take back", BAGD. "God does not withdraw", Phillips.

v30
      pote "at that time" - once, formerly. Probably indefinite; "in the past", Phillips.
      hpeiqhsate (peiqew) aor. "disobedient" - disobey. Possibly "disbelieve", and certainly that would be the sense here; "rejected God", CEV.
      nun de "now" - but now
      th/ toutwn apeiqeia/ "as a result of their disobedience" - by the disobedience of these ones. A dative of cause indicating the reason for an action. Here, Israel's rejection of God in Christ/gospel

v31
      iJna + subj. "in order that" - that. Forming a purpose clause. The rebellion of Israel hides a merciful purpose of God toward Israel itself, as well as toward the Gentiles. Paul's view is that the acceptance of the gospel by the Gentiles will, in the end, goad the Jewish people into accepting Jesus as the messiah. In the end, they will see what they have missed out on and turn to Jesus to be saved.
      tw/ uJmeterw/ eleei "as a result of God's mercy to you" - the to you mercy. The position of this phrase in the Greek text may support its place before "in order that", ie. in the first clause of the sentence, "in the same way, because of the mercy that you have received, the Jews now disobey God, in order that ....", TEV. The NIV, and most others translations, go with a logical positioning. The placement of this phrase in the Greek serves to underline God's mercy.
      nun "now". A difficult variant reading which difficulty may well have prompted a scribe to leave it out. The usual principle probably applies, the more difficult reading is likely to be authentic. The "now" is the present dispensation which will end at the return of Christ. This may well support the argument that the conversion of apostate Jewry is a present and ongoing reality, rather than a final-days phenomenon.