Galatians 4:26 - Matthew Poole's English Annotations on the Holy Bible

The new covenant, or the dispensation of the gospel, or the Christian church, which is above, or from above, which answereth to Sarah, and is said to be above, because revealed from heaven by Christ, sent out of the bosom of the Father, not as the law was revealed upon earth, upon Mount Sinai. Hence apostates from the doctrine of the gospel, are said to turn from him who speaketh from heaven, Hebrews 12:25. Or else it is said to be above, because it is the assembly of the firstborn written in heaven, Galatians 4:23: hence the gospel church is called the heavenly Jerusalem, Galatians 4:22. Of this gospel church the apostle saith, that it is free; i.e. free from the yoke and bondage of the ceremonial law, or from the covenant and curse of the law. Which church, he saith, is the mother of all believers, they embracing the same faith, and walking in the same steps; from whence it was easy for the Galatians to conclude their freedom and liberty also from the law.