Sunan Abu Dawud
656
Sahih+3

Maimunah bint al-Harith reported :the Messenger of Allah (ﷺ) used to pray while. I was by his side in the state of menstruation. Sometime his cloth would touch me when he prostrated. He would pray on a small mat

SahihAl-Albani
SahihMuhammad Muhyi Al-Din Abdul Hamid