Galatians 4:24-27

24 These two women are like pictures of two covenants that God made with his people. Hagar is like the covenant that God made on Mount Sinai. That covenant causes people to become slaves. 25 Hagar is like a picture of Mount Sinai in Arabia. Also, she is like the city of Jerusalem here on earth now, because that city and its people are slaves under the authority of God's Law.

4:24 Mount Sinai was the place where God gave his Law to Israel's people. God's covenant with his people at that time was that they must obey the rules in his Law. So Israel's people were like slaves under the authority of God's Law.
4:25Arabia was a region south-east of Israel.

26 But Abraham's wife, Sarah, is a picture of the new Jerusalem that is above. Sarah was a free person, not a slave, and she is like our mother. 27 It says in the Bible:

‘Be happy, you woman who could not have any children!

You have never known the pain of a child's birth.

But now shout loudly because you are so happy!

Yes, be happy, because the lonely woman now has more children

than the woman who has a husband.’

4:27See Isaiah 54:1.