Sahih al-Bukhari 1652

It is related from Ayyub that Hafsa said, "We used to keep our young women from going out for the two 'Ids. A woman came and stayed at the fortress of the Banu Khalaf and she related that her sister, whose husband had been one of the Companions of the Messenger of Allah, may Allah bless him and grant him peace, and had been on twelve expeditions with the Prophet, may Allah bless him and grant him peace, and who had herself gone with him on six of them, said, 'We used to treat the wounded and care for the sick.' 'My sister asked the Messenger of Allah, may Allah bless him and grant him peace, "Is there any harm in one of us going out if she does not have an outer covering garment?" He said, "Her companion should let her share her outer covering garment and take part in the good actions and gatherings of the believers." When Umm 'Atiyya came, I asked her (or he said, "We asked her"), and she never mentioned the Messenger of Allah, may Allah bless him and grant him peace, without saying, 'By my father', and we said, "Did you hear the Messenger of Allah, may Allah bless him and grant him peace, say such-and-such?" and she said, "Yes, by my father! I heard the Prophet, may Allah bless him and grant him peace, say, 'Young unmarried women, women who seclude themselves - or young girls who seclude themselves - and menstruating women also should go out and take part in the good actions and meetings of the believers, but menstruating women should stay away from the place of prayer.' " ' " [Hafsa said,] "I said, 'Menstruating women?' She said, 'Do they not attend 'Arafa, and so on and so on.' "