Musnad Ahmad 1153:1525

'Abd al-Rahman ibn Mahdi narrated to us, he said: Za'idah narrated to us, from Layth, from 'Abd al-Rahman ibn al-Qasim, from his father, from 'A'ishah, she said: We were with the Messenger of Allah, may Allah bless him and grant him peace, and one of us would menstruate and then become pure, and he would not command us to make up [the prayers], nor would we make them up.