بُلُوغُ الْمَرَامِ
Bulugh al-Maram 489
The Book of Prayer
وَعَنْ أُمِّ عَطِيَّةَ قَالَتْ: { أُمِرْنَا أَنْ نُخْرِجَ اَلْعَوَاتِقَ, وَالْحُيَّضَ فِي الْعِيدَيْنِ; يَشْهَدْنَ الْخَيْرَ وَدَعْوَةَ اَلْمُسْلِمِينَ, وَيَعْتَزِلُ اَلْحُيَّضُ اَلْمُصَلَّى } مُتَّفَقٌ عَلَيْهِ [1] .
Narrated Umm 'Atiyah (RA): We were commanded to bring out on 'Eidul-Fitr and 'Eidul-Adha, the young women and the menstruating women to participate in the goodness and supplications of the Muslims. However, the menstruating women would refrain from the (actual) place of prayer. [Agreed upon].
Sunnah.com reference: Book 2, Hadith 415