Bulugh al-Maram

Narrated 'Uqba bin 'Aamir (RA): His sister took a vow to walk to Allah's House (for pilgrimage) barefooted. Then, she ordered him to consult Allah's Messenger (ﷺ), so he consulted him for a religious verdict and the Prophet (ﷺ) replied, "Let her walk and ride." [Agreed upon, and the wording is Muslim's].