Abu Dawud
Oaths and Vows
Book Number: 015 / Hadith Number: 3290
Narated By Abdullah ibn Abbas : A man came to Prophet (pbuh) and said: Apostle of Allah, my sister has taken a vow to perform hajj on foot. The Prophet (pbuh) said: Allah gets no good from the affliction your sister imposed on herself, so let her perform hajj riding and make atonement for her oath.