Musnad Ahmad 1153:2107

'Abd al-Samad narrated to us, he said: My father narrated to me, he said: Umm al-Hasan narrated to me—'Abd al-Samad said: And she is the grandmother of Abu Bakr al-'Ataki—from Mu'adhah, she said: I asked 'A'ishah about a menstruating woman whose garment is stained with blood? She said: "I used to menstruate while with the Messenger of Allah, may Allah bless him and grant him peace, for three menstrual cycles altogether, and I would not wash a garment of mine." And she said: "The Messenger of Allah, may Allah bless him and grant him peace, used to pray while I had a garment on, part of it was on him and part of it was on me, while I was menstruating and sleeping near him."