Musnad Ahmad 1153:790

Husayn and Abu Ahmad al-Zubayri narrated to us, they said: Isra'il narrated to us, from Abu Ishaq, from al-Bahiy, from Abdullah ibn Umar, from Aisha, she said: The Messenger of Allah, peace and blessings of Allah be upon him, said to me: "Hand me the prayer mat from the mosque." She said: I said: "I am menstruating." He said: "Indeed, your menstruation is not in your hand." Abu Ahmad said: "Indeed, your menstruation is not in your hand."