John Wesley on Genesis 21:10

Cast out the bond - woman - This was a type of the rejection of the unbelieving Jews, who, though they were the seed of Abraham, yet, because they submitted not to the gospel - covenant, were unchurched and disfranchised. And that, which above any thing provoked God to cast them off, was, their mocking and persecuting the gospel - church, God's Isaac, in his infancy.