Galatians 4:25 Now Hagar is Mount Sinai in Arabia; she corresponds to the present Jerusalem, for she is in slavery with her children.
Now Hagar is Mount Sinai (law) in Arabia; and is compelled to answer to Jerusalem (promise) And this point is important and explains why God gave the Law on Mount Sinai that our understanding would be clear, that Sinai was in Arabia, out of the land of promise (Jerusalem) , where the law was given, and seems to be mentioned by Paul with this view, that it might be observed, and teach us that the inheritance od eternal life is not of the law. This is a major point that has been over looked, that Jerusalem the promise and Mount Sinai the law are total opposites one in Arabia and the other in Jerusalem.
And answereth to Jerusalem which now is, and is in bondage with her children; that is, agrees with and accept the promise that the inhabitants of Jerusalem represent, and of all the cities and towns in Judea; and she Hagar , being a bondwoman, represented that state of bondage the Jews were in, when the apostle wrote this. The observance of various days, months, times, and years, and the multitude of sacrifices they were obliged to offer, which yet could not take away sin, nor free their consciences from the load of guilt, but were as an handwriting of ordinances against them; every sacrifice they brought declaring their sin and guilt, and that they deserved to die as the creature did that was sacrificed for them.