It is narrated from Sayyidah Aishah (may Allah be pleased with her) that the Messenger of Allah (peace and blessings be upon him) would lead the Fajr prayer; then, when he (peace and blessings be upon him) finished the prayer, the women of the believers were wrapped in their large sheets and could not be recognised because of the darkness.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2137