I want to say this to start I am not a dispensationalist, I do not claim to be anything but a Christian, I go to a Reformed Church. With that said lets look it what the Bible says.
Here is the problem with the OP Galatians 4:24 “Now this may be interpreted allegorically: these women are two covenants. One is from Mount Sinai, bearing children for slavery; she is Hagar.”
It does not say theologially. Here's what BAGD says about the Greek word used, calling it "mythical" so Paul did not mean it literally, he says this maybe interpreted allegorically, again not literially or theologically.
I understand that Genesis 12:7 is speaking of Christ as Galatians 3:16 says. It is very clear that Genesis 15 and 17 are speaking of Isacc as Abraham's offspring, the covenant was ratified in Genesis 15:3-5 speaks of Abraham's offspring being as the stars in the stars.
“And Abram said, “Behold, you have given me no offspring, and a member of my household will be my heir.”4 And behold, the word of the Lord came to him: “This man shall not be your heir; your very own son shall be your heir.”5 And he brought him outside and said, “Look toward heaven, and number the stars, if you are able to number them.” Then he said to him, “So shall your offspring be.”
The Lord ratifies that covenant in Genesis 15:17-21 also adding a maps of the land as part of this covenant.
“When the sun had gone down and it was dark, behold, a smoking fire pot and a flaming torch passed between these pieces.18 On that day the Lord made a covenant with Abram, saying, “To your offspring I give this land, from the river of Egypt to the great river, the river Euphrates,19 the land of the Kenites, the Kenizzites, the Kadmonites,20 the Hittites, the Perizzites, the Rephaim,21 the Amorites, the Canaanites, the Girgashites and the Jebusites.”
Now in Genesis 17:4-8 the Lord tells Abraham that he will be the father of many nations, so this is not speaking of offspring as in one Chirst. Then the Lord tells him that the covenant will be between Abraham his offspring throughout their generations for an everlasting covenant, notice the use of the plural personal pronoun by the use of "their", so not singual either.
“Behold, my covenant is with you, and you shall be the father of a multitude of nations.5 No longer shall your name be called Abram, but your name shall be Abraham, for I have made you the father of a multitude of nations.6 I will make you exceedingly fruitful, and I will make you into nations, and kings shall come from you.7 And I will establish my covenant between me and you and your offspring after you throughout their generations for an everlasting covenant, to be God to you and to your offspring after you.8 And I will give to you and to your offspring after you the land of your sojournings, all the land of Canaan, for an everlasting possession, and I will be their God.”
Then Genesis 17:9-14 the Lord gives Abraham the everlasting covenant and the sign for it, circumcision. Then in Genesis 17:19 the Lord tells Abraham that Sarah would have a son as his hier and names him as the one that the everlasting covenant would established with and his offspring after him. Clearly this is not speaking of Christ.
“God said, “No, but Sarah your wife shall bear you a son, and you shall call his name Isaac. I will establish my covenant with him as an everlasting covenant for his offspring after him.”
So here is the big question, why are there a people that are of the offspring of Abraham and they still circumcise their male children. Look at all the old art, Greek statues they were not circumcised.
What does all this mean, the are a people that are the elect of God from the beginning of time. Was Job Jews? Who knows bt he was one of the elect, thier are people that are the physical offspring of Abraham that are elect of God and there are some of those same people that have been partially hardened to the Gospel. Remeber this warning by Paul.
Romans 11:24-25, 28-33 “For if you were cut from what is by nature a wild olive tree, and grafted, contrary to nature, into a cultivated olive tree, how much more will these, the natural branches, be grafted back into their own olive tree.
25 Lest you be wise in your own sight, I do not want you to be unaware of this mystery, brothers: a partial hardening has come upon Israel, until the fullness of the Gentiles has come in.”
Romans 11:28-33 “As regards the gospel, they are enemies for your sake. But as regards election, they are beloved for the sake of their forefathers.29 For the gifts and the calling of God are irrevocable.30 For just as you were at one time disobedient to God but now have received mercy because of their disobedience,31 so they too have now been disobedient in order that by the mercy shown to you they also may now receive mercy.32 For God has consigned all to disobedience, that he may have mercy on all.
33 Oh, the depth of the riches and wisdom and knowledge of God! How unsearchable are his judgments and how inscrutable his ways!”
Do not be wise in your own eyes about Israel, they will be grafted back in because the Lord is not done with them yet. This has nothing to do with dispensationalism and everything to do with the Bible. Am I looking for aother Temple? No! Do I look to Israel as a time clock for the end of days? No! Why? Because I do not fully understand it all, but I will not be wise in my own eyes when it comes to Israel and that is not dispensationalism.
