Children of the Free Woman

Galatians 4:30-31 NASB
30 But what does the Scripture say?
"CAST OUT THE BONDWOMAN AND HER SON,
FOR THE SON OF THE BONDWOMAN SHALL NOT BE AN HEIR WITH THE SON OF THE FREE WOMAN."
31 So then, brethren, we are not children of a bondwoman, but of the free woman.

If you read Genesis 21:5-10 with the previous blog, you should recognize this quote from Genesis 21:10.

Genesis 21:10 NASB
Therefore she said to Abraham, "Drive out this maid and her son, for the son of this maid shall not be an heir with my son Isaac."

In Genesis 21:12, God verifies for Abraham that what Sarah said is true--his descendants would be named through Isaac, not Ishamael. This is restating a promise that God made to Abraham in Genesis 17:19.

In the case of Paul and the Galatians, who is representing "the bondwoman and her son"?
What is Paul telling the Galatians to do to those who represent her and her son?
Why should they do that?
Who is the heir? What had Paul previously told them in Genesis 4:4-7?
Who is their mother?
Have they been born into freedom or slavery?
In my NASB version, John 8:35 is listed as a cross reference for Genesis 4:30. Read a bit more than that--read and think about what Jesus said in John 8:31-36.
How is what Jesus is saying similar to what Paul is telling the Galatians?