The Two Festivals (Eids)
Bukhari :: Book 2 :: Volume 15 :: Hadith 97
Narrated Um-'Atiya:
We were ordered to go out (for 'Id) and also to take along with us the menstruating women, mature girls and virgins staying in seclusion. (Ibn 'Aun said, "Or mature virgins staying in seclusion)." The menstruating women could present themselves at the religious gathering and invocation of Muslims but should keep away from their Musalla.