Galatians 4:30
Nevertheless what saith the scripture? Cast out the bondwoman and her son: for the son of the bondwoman shall not be heir with the son of the freewoman. Nevertheless what saith the scripture? Cast out the bondwoman and her son: for the son of the bondwoman shall not be heir with the son of the freewoman.
As part of Galatians 4:21-31 the command to cast out the bondwoman and her son gives clear and convincing light on the covenants, plain light that every candid, unprejudiced mind would receive. It sets forth the true position on the covenants. It belongs to the discussion of the law in Galatians.
Turning from this light comes from fear of having to accept what it teaches about the law and from not being truly converted before God. That turning leads to imitating the Jews in misconstruing Scripture and twisting words to a false meaning, to deceiving the people and making false issues, and to clouding and misleading minds. Yet this subject of the law must not be made a test of faith or revived as a divisive controversy, since treating it that way can again divide believers.