It is narrated from Sayyidah Aishah (may Allah be pleased with her) that the Messenger of Allah (peace and blessings be upon him) used to pray at night while I was at his side, and I was menstruating. I had a sheet over me, part of which was over the Prophet (peace and blessings be upon him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4119