Paul Henebury has some good insights on Paul’s teaching in Galatians three on the idea of “seed” and the Abrahamic covenant. He has written three more articles on the subject plus an addendum interacting with objections. They supplement my posts I am currently compiling that detail the premillennial understanding of the land promises.
Galatians 3, the Land, and the Abrahamic Covenant: What was Paul Thinking?
Paul summarizes his main point in the fourth post by writing,
In disagreeing with Gunn I am not saying that he is not justified in attending to the places in Genesis where the apostle appears to be getting his language about “and to your seed” from: that is, from Genesis 12 through 22. The problem comes in when he extrapolates from the false notion that Paul is quoting from only two places in the Septuagint and claims the land promise of these “seed” passages must be transferred to the Church and turned magically into promises of heaven. When Christians insist that this must be done they are going beyond the teaching of the NT, not to say the apostle Paul elsewhere (e.g. Romans 11). They are also claiming the OT cannot be properly understood without the New – a claim which sounds pious enough, until it is analyzed in light of its logical outcome…
My response (which, remember, was just a part response) is that in order for the Abrahamic covenant to be tied to the Church (especially its Gentile contingent), that covenant must be connected to the New covenant in Christ. If that is true then Paul is thinking along these lines when he cites the four words “and to your seed” from Genesis. He most probably does not have an exact reference in mind, as he did with his earlier quotation of Genesis 15:6, but rather has in view the repeated use of the phrase through the Abrahamic narrative (if I had to make a guess which passage Paul may have been citing I would go for Gen. 22:18).