Musannaf Ibn Abi Shayba 9:913

Waki’ narrated to us, from al-Awza’i, from ‘Abdah, that Umm Salamah said: "I became *nafisah* (menstruating) while I was with the Messenger of Allah, may Allah bless him and grant him peace, meaning I menstruated in my bed. So I went to move away, and he said: 'Stay in your place; it is sufficient for you to put a garment over yourself.'"