13 Her husband may confirm or nullify any vow she makes or any sworn pledge to deny herself.a

Read Numbers 30:13 Using Other Translations

Every vow, and every binding oath to afflict the soul, her husband may establish it, or her husband may make it void.
Any vow and any binding oath to afflict herself, her husband may establish, or her husband may make void.
So her husband may either confirm or nullify any vows or pledges she makes to deny herself.