It has to do with several contextual features, to wit:
- Prior to 1 Cor. 11, Paul’s been dealing with crimes and misdemeanors of various parties, factions, or individuals within the Corinthian congregation. Beginning in Chapter 11 and running through chapter 14, perhaps 15 as well, Paul is dealing with congregation-wide problems, most of them involving the conduct of the congregation when it is gathered for worship.
For this reason, I cannot treat 1 Corinthians 11:1-16 as dealing with married women to the exclusion of single women, any more than it does with married men to the exclusion of single men or vice-versa. No, it’s the whole passle of them - old, young, married, single. All of them when gathered for worship.
- Paul’s statements about women in this passage are “categorical” with respect to that sex. Single women are created for the man’s sake, just as much as the the married woman. The single woman’s hair is her glory, just as much as it is for the married woman. The single woman’s hair is a covering, not just the married woman’s.
Indeed, if you can discern that glory - whose is on display in worship - is the key to this exhortation, it becomes mandatory that all women have a covering. That way all three glories are rightly displayed in the worship service - the man’s glory is covered (i.e. the woman), the woman’s glory is covered (i.e. her hair), and only God’s glory is uncovered (i.e. the man). Who is married to whom (or not), is an irrelevancy. What’s at issue is whose glory is covered or uncovered.