Sahih Muslim
The Book of Pilgrimage (Kitab Al-Hajj)
Book Number: 007 / Hadith Number: 3105
Abu Huraira (Allah be pleased with him) reported Allah's Apostle (may peace be upon him) as saying: It is not lawful for a woman who believes in Allah and the Hereafter to undertake a day's journey except in the company of a Mahram.