Hafsa bint Umar bin Khattab reported,

We used to prevent our young unmarried women from going out for the two Eid prayers. Then a woman arrived and stayed at the fortress of Banu Khalaf, and she narrated from her sister, whose husband had taken part in twelve military expeditions with the Prophet ﷺ, and her sister had accompanied him on six of them.Her sister said, "We used to tend to the wounded and look after the sick. I asked the Prophet ﷺ, 'Is there any harm if one of us does not go out because she has no outer garment?'"He replied, "Let her companion lend her one of her own garments so she may witness the goodness and the supplication of the Muslims."When Umm Atiya arrived, I asked her, "Did you hear this from the Prophet ﷺ?"She said, "By my father, yes." She never mentioned him without saying, "By my father." She continued, "I heard him say, 'Let the young unmarried women, those kept in seclusion, and the menstruating women come out,'" or he said, "the young unmarried women kept in seclusion, and the menstruating women, so they may witness the goodness and the supplication of the believers, but let the menstruating women keep away from the prayer area."Hafsa said, "I asked, 'The menstruating women?'"She replied, "Do they not witness Arafah and such and such?"

Bukhari 324

Sahih

حدثنا محمد هو ابن سلام قال أخبرنا عبد الوهاب عن أيوب

عن حفصة قالت

كنا نمنع عواتقنا أن يخرجن في العيدين فقدمت امرأة فنزلت قصر بني خلف فحدثت عن أختها وكان زوج أختها غزا مع النبي ﷺ ثنتي عشرة غزوة وكانت أختي معه في ست قالت كنا نداوي الكلمى ونقوم على المرضى فسألت أختي النبي ﷺ أعلى إحدانا بأس إذا لم يكن لها جلباب أن لا تخرج قال لتلبسها صاحبتها من جلبابها ولتشهد الخير ودعوة المسلمين فلما قدمت أم عطية سألتها أسمعت النبي ﷺ قالت بأبي نعم وكانت لا تذكره إلا قالت بأبي سمعته يقول يخرج العواتق وذوات الخدور أو العواتق ذوات الخدور والحيض وليشهدن الخير ودعوة المؤمنين ويعتزل الحيض المصلى قالت حفصة فقلت الحيض فقالت أليس تشهد عرفة وكذا وكذا

البخاري 324صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Menstruation
Chapter
Menstruating women attending the two Eids and the supplication of the Muslims, while keeping away from the prayer area
Numbering
Darussalam 324
Bukhari 324