What does it mean that his son by the slave woman was born in the ordinary way?

In the Greek text, Paul uses the term flesh when describing the birth of the son by the slave woman. This has prompted some commentators to say that the emphasis falls on the sinful human attempt by Abraham to fulfil the promise God made to him. Though this thought is certainly included, given the comparison to promise, it is more likely that Paul is affirming that the birth of Ishmael was according to a natural, ordinary process.¹ There was no need for a special miracle because Hagar was not beyond the age of bearing children.