Pilgrimmage (Hajj)
Bukhari :: Book 2 :: Volume 26 :: Hadith 814
Narrated Ibn Abbas:
A menstruating woman was allowed to leave Mecca if she had done Tawaf-al-Ifada. Tawus (a sub-narrator) said from his father, "I heard Ibn 'Umar saying that she would not depart. Then later I heard him saying that the Prophet had allowed them (menstruating women) to depart."