Sahih Bukhari
Menstrual Periods
Volume: 001 / Book Number: 006 / Hadith Number: 326
Narrated Ibn 'Abbas:
A woman is al lowed to leave (go back home) if she gets menses (after Tawaf-AlIfada). Ibn 'Umar formerly used to say that she should not leave but later on I heard him saying, "She may leave, since Allah's Apostle gave them the permission to leave (after Tawaf-AlIfada."