From Sahih Bukhari (Hadith 379):
Narrates `Abdullah bin Shaddad:Maimuna said, "Allah's Messenger (ﷺ) was praying while I was in my menses, sitting beside him and sometimes his clothes would touch me during his prostration." Maimuna added, "He prayed on a Khumra (a small mat sufficient just for the face and the hands while prostrating during prayers)
Reference: Bukhari 379