Genesis 21:10 - Wesley's Explanatory Notes

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.