Sahih Muslim
The Book of Menstruation (Kitab Al-Haid)
Book Number: 003 / Hadith Number: 588
'A'isha reported: The Messenger of Allah (may peace be upon him) ordered me that I should get him the mat from the mosque. I said: I am menstruating. He (the Holy Prophet) said: Do get me that, for menstruation is not in your hand.