Q: Where does it say in the Bible that a woman is not to cut her hair? I know it says a woman’s hair is her glory (I think). Can you please help?
A: I Corinthians 11:15 is the scripture you are referring to:
but if a woman has long hair, it is her glory? For her hair is given to her for a covering. -ESV
It was the common custom in the first century for men to generally have shorter hair than women and so it was in the churches also. Paul is teaching about proper deportment in worship in this passage.
Women in the first century covered their head in public. Those who uncovered or let their hair down in public were considered loose morally or promiscuous. Christians abided by these common customs in the first century and Paul is using them as proper examples here in I Corinthians 11.
The only other NT references to woman’s hair are 1Tim. 2:9 and 1Peter 3:3. They refer to ‘braided’ hair and extravagant dress as a wealthy Greek and Roman custom that might be avoided particularly at church.
There is no specific teaching in the New Testament prohibiting women from cutting their hair.