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.

حَدَّثَنَا عَمْرُو بْنُ عَوْنٍ، حَدَّثَنَا خَالِدٌ، عَنِ الشَّيْبَانِيِّ، عَنْ عَبْدِ اللَّهِ بْنِ شَدَّادٍ، حَدَّثَتْنِي مَيْمُونَةُ بِنْتُ الْحَارِثِ، قَالَتْ كَانَ رَسُولُ اللَّهِ ﷺ يُصَلِّي وَأَنَا حِذَاءَهُ وَأَنَا حَائِضٌ وَرُبَّمَا أَصَابَنِي ثَوْبُهُ إِذَا سَجَدَ وَكَانَ يُصَلِّي عَلَى الْخُمْرَةِ .