Gal 4:24  which things are symbolic. For these are the two covenants: the one from Mount Sinai which gives birth to bondage, which is Hagar— 
Gal 4:25  for this Hagar is Mount Sinai in Arabia, and corresponds to Jerusalem which now is, and is in bondage with her children—
Gal 4:26  but the Jerusalem above is free, which is the mother of us all.
Gal 4:27  For it is written: "REJOICE, O BARREN, YOU WHO DO NOT BEAR! BREAK FORTH AND SHOUT, YOU WHO ARE NOT IN LABOR! FOR THE DESOLATE HAS MANY MORE CHILDREN THAN SHE WHO HAS A HUSBAND."
Gal 4:28  Now we, brethren, as Isaac was, are children of promise.
Gal 4:29  But, as he who was born according to the flesh then persecuted him who was born according to the Spirit, even so it is now.
Gal 4:30  Nevertheless what does the Scripture say? "CAST OUT THE BONDWOMAN AND HER SON, FOR THE SON OF THE BONDWOMAN SHALL NOT BE HEIR WITH THE SON OF THE FREEWOMAN." 
Gal 4:31  So then, brethren, we are not children of the bondwoman but of the free.
Why did Paul compel the Galatian believers to "cast out" the Sinai Covenant of "bondage"?
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