Sahih Muslim 890bBook 8, Hadith 11
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى، أَخْبَرَنَا أَبُو خَيْثَمَةَ، عَنْ عَاصِمٍ الأَحْوَلِ، عَنْ حَفْصَةَ بِنْتِ، سِيرِينَ عَنْ أُمِّ عَطِيَّةَ، قَالَتْ كُنَّا نُؤْمَرُ بِالْخُرُوجِ فِي الْعِيدَيْنِ وَالْمُخَبَّأَةُ وَالْبِكْرُ قَالَتِ الْحُيَّضُ يَخْرُجْنَ فَيَكُنَّ خَلْفَ النَّاسِ يُكَبِّرْنَ مَعَ النَّاسِ .
We were commanded to go out as well as the hidden away ladies and those unmarried. She said menstruating women were to come out amongst you, but remain behind people and pronounce takbir (Allah-o-Akbar) along with them.