Albert Barnes Commentary Galatians 4:26

"But the Jerusalem that is above is free, which is our mother." — Galatians 4:26 (ASV)

But Jerusalem which is above. The spiritual Jerusalem; the true church of God. Jerusalem was the place where God was worshipped, and therefore it became synonymous with the word church, or is used to represent the people of God. The word translated "above" (anō) means, properly, up above, that which is above; and therefore heavenly, celestial (Colossians 3:1–2; John 8:23).

Here it means the heavenly or celestial Jerusalem. Revelation 21:2: And I John saw the holy city, new Jerusalem, coming down from God, out of heaven.Hebrews 12:22: You are come unto Mount Sion, and unto the city of the living God, the heavenly Jerusalem. Here it is used to denote the church, as being of heavenly origin.

Is free. The spirit of the gospel is that of freedom. It is freedom from sin, freedom from the bondage of rites and customs, and it tends to promote universal freedom. See the notes on Galatians 4:7. Compare John 8:32, John 8:36; see also the notes on 2 Corinthians 3:17.

Which is the mother of us all. Of all who are true Christians, whether we are by birth Jews or Gentiles. We should not, therefore, yield ourselves to any degrading and abasing servitude of any kind. Compare the notes on 1 Corinthians 6:12.