Sahih Bukhari Volume 002, Book 015, Hadith Number 096.
Narated By Aiyub : Hafsa bint Sirin said, "On Id we used to forbid our girls to go out for 'Id prayer. A lady came and stayed at the palace of Bani Khalaf and I went to her. She said, 'The husband of my sister took part in twelve holy battles along with the Prophet and my sister was with her husband in six of them. My sister said that they used to nurse the sick and treat the wounded. Once she asked, 'O Allah's Apostle! If a woman has no veil, is there any harm if she does not come out (on 'Id day)?' The Prophet said, 'Her companion should let her share her veil with her, and the women should participate in the good deeds and in the religious gatherings of the believers.' " Hafsa added, "When Um-'Atiya came, I went to her and asked her, 'Did you hear anything about so-and-so?' Um-'Atlya said, 'Yes, let my father be sacrificed for the Prophet (p.b.u.h). (And whenever she mentioned the name of the Prophet she always used to say, 'Let my father be' sacrificed for him). He said, 'Virgin mature girls staying often screened (or said, 'Mature girls and virgins staying often screened... Aiyub is not sure as which was right) and menstruating women should come out (on the 'Id day). But the menstruating women should keep away from the Musalla. And all the women should participate in the good deeds and in the religious gatherings of the believers'." Hafsa said, "On that I said to Um-'Atiya, 'Also those who are menstruating?' " Um-'Atiya replied, "Yes. Do they not present themselves at 'Arafat and elsewhere?".