4:25 For this Agar is mount Sinai in Arabia, and {c} answereth to Jerusalem which now is, and {d} is in bondage with her children.
(c) Look how the case stands between Hagar and her children; even so stands it between Jerusalem and hers.
(d) That is, Sinai.
4:25 For this Agar is mount Sinai in Arabia. Represents Sinai. This Mount Sinai is in Arabia, the very home of Ishmael and his race. Some also add that one name of the mountain is Hagar, but this is not certain.
Answereth to Jerusalem which is now. Represents the earthly Jerusalem, under bondage, bondage to the law herself, and also her children, as Hagar and her child were under bondage.
4:25 For this is mount Sinai in Arabia - That is, the type of mount Sinai. And answereth to - Resembles Jerusalem that now is, and is in bondage - Like Agar, both to the law and to the Romans.
4:21-27 The difference between believers who rested in Christ only, and those who trusted in the law, is explained by the histories of Isaac and Ishmael. These things are an allegory, wherein, beside the literal and historical sense of the words, the Spirit of God points out something further. Hagar and Sarah were apt emblems of the two different dispensations of the covenant. The heavenly Jerusalem, the true church from above, represented by Sarah, is in a state of freedom, and is the mother of all believers, who are born of the Holy Spirit. They were by regeneration and true faith, made a part of the true seed of Abraham, according to the promise made to him.